MRI-Guided Medical Interventional Systems and Methods

ABSTRACT

An MRI-guided interventional system includes a trajectory guide frame for guiding an interventional device with respect to a patient in an MRI-guided procedure and including a base, a platform, a targeting cannula, and a stabilizer mechanism. The platform is mounted on the base and includes a support table and a moving plate that is translatable relative to the support table and the base along a translational axis. The targeting cannula is mounted on the moving plate for movement therewith and includes an elongate guide bore defining a trajectory axis. The stabilizer mechanism is operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base. The frame is operable to translate the moving plate along the translational axis relative to the base to position the trajectory axis. The translational axis is transverse to the trajectory axis.

RELATED APPLICATIONS

This application is a continuation application of U.S. patent application Ser. No. 12/236,950, filed Sep. 24, 2008, which is a continuation-in-part application of U.S. patent application Ser. No. 12/134,412, filed Jun. 6, 2008, which claims the benefit of and priority to U.S. Provisional Patent Application No. 60/933,641, filed Jun. 7, 2007, and to U.S. Provisional Patent Application No. 60/974,821, filed Sep. 24, 2007, the disclosures of which are incorporated herein by reference as if set forth in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to medical systems and methods and, more particularly, to in vivo medical systems and methods.

BACKGROUND OF THE INVENTION

Deep Brain Stimulation (DBS) is becoming an acceptable therapeutic modality in neurosurgical treatment of patients suffering from chronic pain, Parkinson's disease or seizure, and other medical conditions. Other electro-stimulation therapies have also been carried out or proposed using internal stimulation of the sympathetic nerve chain and/or spinal cord, etc.

One example of a prior art DBS system is the Activa® system from Medtronic. Inc. The Activa® system includes an implantable pulse generator stimulator that is positioned in the chest cavity of the patient and a lead with axially spaced apart electrodes that is implanted with the electrodes disposed in neural tissue. The lead is tunneled subsurface from the brain to the chest cavity connecting the electrodes with the pulse generator. These leads can have multiple exposed electrodes at the distal end that are connected to conductors which run along the length of the lead and connect to the pulse generator placed in the chest cavity.

It is believed that the clinical outcome of certain medical procedures, particularly those using DBS, may depend on the precise location of the electrodes that are in contact with the tissue of interest. For example, to treat Parkinson's tremor, presently the DBS probes are placed in neural tissue with the electrodes transmitting a signal to the thalamus region of the brain. DBS stimulation leads are conventionally implanted during a stereotactic surgery, based on pre-operative MRI and CT images. These procedures can be long in duration and may have reduced efficacy as it has been reported that, in about 30% of the patients implanted with these devices, the clinical efficacy of the device/procedure is less than optimum. Notwithstanding the above, there remains a need for alternative MRI-guided interventional tools for DBS, as well as for other interventional medical procedures.

SUMMARY OF THE INVENTION

In view of the above, MRI-guided interventional systems and methods are provided. Embodiments of the present invention provide methods, devices and systems for highly localized placement and/or delivery of diagnostic or therapeutic devices or substances.

According to embodiments of the present invention, an MRI-guided interventional system includes a frame with a cooperating targeting cannula. The frame is configured to be secured to the body of a patient, and is configured to translate and rotate such that the targeting cannula can be positioned to a desired intrabody trajectory. The frame may include one or more MRI-visible fiducial markers that allow frame location/orientation to be determined within an MRI image.

Embodiments of the present invention may be particularly suitable for placing neuro-modulation leads, such as Deep Brain Stimulation (“DBS”) leads, implantable parasympathetic or sympathetic nerve chain leads and/or CNS stimulation leads, as well as other devices within the brain.

Embodiments of the present invention may be suitable for a number of interventional procedures in many locations inside the body including, but not limited to, brain, cardiac, spinal, urethral, and the like. Embodiments of the present invention may be suitable for a number of MRI-guided drug delivery procedures, MRI-guided ablation procedures, etc.

A plurality of user-activatable actuators are operably connected to the frame and are configured to translate and rotate the frame relative to the body of a patient so as to position the targeting cannula to a desired intrabody trajectory. In some embodiments, the actuators are dials or thumbscrew-type devices that allow manual manipulation thereof. In other embodiments, the actuators are manipulated remotely using remote controls and cables.

The targeting cannula includes an axially-extending guide bore therethrough that is configured to guide placement of an interventional device in vivo. Various instrumentation and equipment (e.g., stimulation leads, ablation probes or catheters, injection or fluid delivery devices, biopsy needles, extraction tools, etc.) can be inserted through the targeting cannula to execute diagnostic and/or surgical procedures.

According to some embodiments of the present invention, the frame includes a base, a yoke movably mounted to the base and that is rotatable about a roll axis, and a platform movably mounted to the yoke and that is rotatable about a pitch axis. The platform includes an X-Y support table that is configured to move in an X-direction and Y-direction relative to the platform. The base has a patient access aperture formed therein, and is configured to be secured to the body of a patient such that the aperture overlies an opening in the body. A roll actuator is operably connected to the yoke and is configured to rotate the yoke about the roll axis. A pitch actuator is operably connected to the platform and is configured to rotate the platform about the pitch axis. An X-direction actuator is operably connected to the platform and is configured to move the X-Y support table in the X-direction, A Y-direction actuator is operably connected to the platform and is configured to move the X-Y support table in the Y-direction.

The base may include a plurality of locations for attachment to a body of a patient via fasteners. In some embodiments, one or more attachment locations may include multiple adjacent apertures configured to receive a fastener therethrough. For embodiments where the frame is configured to be attached to the skull of a patient, the base can be configured to be secured to the skull of a patient such that the patient access aperture overlies a burr hole formed in the patient skull.

According to some embodiments of the present invention, the yoke includes a pair of spaced apart arcuate arms. The platform engages and moves along the yoke arcuate arms when rotated about the pitch axis. The base includes at least one arcuate arm. The yoke engages and moves along the base arcuate arm when rotated about the roll axis.

According to some embodiments of the present invention, at least one of the yoke arcuate arms includes a thread pattern formed in a surface thereof. The pitch actuator includes a rotatable worm with teeth configured to engage the thread pattern. Rotation of the worm causes the platform to rotate about the pitch axis. Similarly, at least one of the base arcuate arms includes a thread pattern formed in a surface thereof. The roll actuator includes a rotatable worm with teeth configured to engage the thread pattern, and wherein rotation of the worm causes the yoke to rotate about the roll axis.

In some embodiments, the actuators are color-coded such that each different actuator has a respective different color. This allows a user to quickly determine which actuator is the correct one for a particular desired movement of the frame.

According to some embodiments of the present invention, an ergonomic remote control unit is provided that allows a user to remotely translate and rotate the frame such that the targeting cannula can be positioned to a desired intrabody trajectory. The remote control unit includes a plurality of position controls. Each control is operably connected to a respective frame actuator by a respective cable. One or more of the position controls can include both “gross” and “fine” adjustments.

Movement of a position control operates a respective actuator via a respective control cable. For example, the remote control unit includes a roll adjustment control, a pitch adjustment control, an X-direction adjustment control, and a Y-direction adjustment control. A roll control cable is operably connected to the roll adjustment control and to the roll actuator. Movement of the roll adjustment control operates the roll actuator via the roll control cable. A pitch control cable is operably connected to the pitch adjustment control and to the pitch actuator. Movement of the pitch adjustment control operates the pitch actuator via the pitch control cable. An X-direction control cable is operably connected to the X-direction control and to the X-direction actuator. Movement of the X-direction adjustment control operates the X-direction actuator via the X-direction control cable. A Y-direction control cable is operably connected to the Y-direction control and to the Y-direction actuator. Movement of the Y-direction adjustment control operates the Y-direction actuator via the Y-direction control cable.

In some embodiments, the roll adjustment control, pitch adjustment control, X-direction adjustment control, and Y-direction adjustment control are manually-operated thumbwheels, and rotation of each thumbwheel by a user causes corresponding axial rotation of a respective control cable and corresponding axial rotation of a respective actuator. In other embodiments, one or more of the roll adjustment control, pitch adjustment control, X-direction adjustment control, and Y-direction adjustment control are electric motor-assisted, rotatable controls.

In some embodiments, locking mechanisms are associated with the remote unit position controls, and are configured to prevent user operation of the controls when in a locked position.

In some embodiments, each control cable has a geometrically shaped rigid end that is configured to removably engage a free end of a respective actuator. Each control cable rigid end may have a shape that is different from the other control cable rigid ends such that each control cable free end can only removably engage one of the respective actuator free ends. Each control cable includes a flexible elastomeric collar that is configured to surround a respective actuator free end and to maintain engagement of a cable end to a respective actuator free end. Each flexible collar can be rolled or folded back then released to cover and conformably compress against an actuator free end to hold the end of the cable in position; then the collar can be pushed back to easily release the cable from an actuator free end.

According to some embodiments, a safety lanyard may be used to connect the remote control module to a rigid object, such as a patient support frame or head coil (or even the gantry or gantry housing) to prevent over extension of the cables or unwanted adjustments to the trajectory.

According to some embodiments, a drape is provided that is configured to be positioned near the body of a patient within a magnet of an MRI scanner. The drape includes a pocket that is configured to removably receive the remote control unit therein. The drape also includes one or more apertures through which the cables extend from the remote control unit to the frame.

According to some embodiments of the present invention, a camera and/or video imaging device is removably secured to the frame via a bracket. The bracket includes a sleeve that is configured to slidably receive the imaging device therein.

An elongated tubular member extends through the platform and yoke and is secured to the X-Y table of the frame. The targeting cannula is slidably secured within the tubular member and is movable between extended and retracted positions. The targeting cannula is configured to translate in response to translational movement of the X-Y support table and to rotate in response to rotational movement of the yoke and platform to define different axial trajectories extending through the patient access aperture of the base. The tubular member is configured to lock the targeting cannula in an extended position and in a retracted position.

A depth stop is removably secured within a proximal end of the tubular member. The depth stop receives a sheath therein, and is configured to limit the distance that the sheath can extend into the body of a patient. The sheath is configured to receive an elongated interventional device (e.g., imaging probe, stimulation lead, ablation device, injection device, etc.). In some embodiments, the sheath is removable. A locking mechanism is removably secured to the depth stop and is configured to prevent axial movement of an elongated interventional device extending through the sheath.

According to some embodiments of the present invention, an MRI-guided interventional system includes a frame with a cooperating targeting cannula that has a guide bore therethrough that is configured to guide placement of an interventional device in vivo. The frame is configured to rotate such that the targeting cannula can be positioned to a desired intrabody trajectory. The frame includes a base having a patient access aperture formed therein, wherein the base is configured to be secured to the body of a patient; a yoke movably mounted to the base and rotatable about a roll axis; and a platform movably mounted to the yoke and rotatable about a pitch axis. A plurality of user-activatable actuators are operably connected to the frame and are configured to rotate the frame relative to the body of the patient so as to position the targeting cannula to a desired intrabody trajectory. In some embodiments, the actuators are color-coded such that each actuator has a respective different color. In some embodiments, the frame includes a roll actuator operably connected to the yoke and configured to rotate the yoke about the roll axis; and a pitch actuator operably connected to the platform and configured to rotate the platform about the pitch axis.

In some embodiments, the system includes a remote control unit comprising a plurality of elongate control devices. Each control device includes first and second elongate rods axially connected at respective first ends via a first cable. The first rod second end is operably connected to a respective actuator via a second cable. Rotational movement of the second end of the second rod operates the actuator via the second cable. Each second cable may have a geometrically shaped rigid end configured to removably engage a free end of a respective actuator.

MRI-guided interventional methods, according to embodiments of the present invention, include affixing a frame with a cooperating targeting cannula to the body of a patient, wherein the frame is configured to translate and rotate such that the targeting cannula can be positioned to a desired intrabody access path trajectory. The targeting cannula includes a guide bore therethrough that is configured to guide placement of an interventional device in vivo. The targeting cannula position is adjusted (e.g., rotated about a roll axis, rotated about a pitch axis, and/or translated in X-Y directions) so that the targeting cannula is aligned with the desired access path trajectory while the patient is positioned within a magnetic field associated with an MRI scanner. Once the targeting cannula is repositioned, an interventional device is inserted through the targeting cannula guide bore and into the body of the patient for therapeutic and/or diagnostic purposes. The targeting cannula is movable between retracted and extended positions, and is moved to the extended position and locked in the extended position prior to the adjusting the access path trajectory thereof.

The necessary rotational and translational adjustments required to reposition the targeting cannula to the desired access path trajectory are displayed to a user via a graphical user interface. Both the actual access path trajectory and desired access path trajectory can be displayed, as well. In addition, the user can view the actual trajectory changing as he/she adjusts the position of the targeting cannula. In some embodiments, an indication of when the actual trajectory is aligned with a desired trajectory can be displayed to the user.

According to some embodiments, an MRI-guided interventional system for use with a body of patient and an interventional device includes a base and a targeting cannula. The base is configured to be secured to the body of the patient. The targeting cannula has an elongate guide bore extending axially therethrough and an inlet and an outlet at opposed ends of the guide bore. The guide bore defines a trajectory axis extending through the inlet and the outlet and being configured to guide placement of the interventional device. The frame is operable to move the targeting cannula relative to the base to position the trajectory axis to a desired intrabody trajectory to guide placement of the interventional device in vivo. The inlet tapers from an outer diameter distal from the guide bore to an inner diameter proximate the guide bore to guide and facilitate insertion of the interventional device into the guide bore.

The system may include an elongate interventional device configured to be serially inserted through the inlet, the guide bore and the outlet and into the body of the patient in vivo.

In some embodiments, the trajectory guide frame further includes a tubular cannula guide member defining a cannula guide member passage and having an inlet and outlet on opposed ends of the cannula guide member passage, and the targeting cannula is slidably mounted within the cannula guide member passage to move between extended and retracted positions. In some embodiments, the targeting cannula has a main body portion and an extension portion, the extension portion including the inlet of the targeting cannula, and the main body portion has a primary outer diameter that is greater than a diameter of the inlet of the cannula guide member and the extension portion has a reduced outer diameter that is less than the primary outer diameter and is sized to be received in the inlet of cannula guide member when the targeting cannula is in the retracted position.

The inlet of the cannula guide member can have a diameter that is at least as great as the outer diameter of the inlet of the targeting cannula.

According to embodiments of the present invention, an MRI-guided interventional system for use with a body of patient and an interventional device includes a base, a targeting cannula, and a bracket. The base is configured to be secured to the body of the patient. The targeting cannula has an elongate guide bore extending axially therethrough, defining a trajectory axis, and being configured to guide placement of the interventional device. The frame is operable to move the targeting cannula relative to the base to position the trajectory axis to a desired intrabody trajectory to guide placement of the interventional device in vivo. The bracket is secured to the trajectory guide frame such that the bracket is rotatable about the trajectory axis and axially fixed with respect to the trajectory axis. The bracket is configured to receive a light transmission scope to secure the light transmission scope to the trajectory guide frame.

In some embodiments, the trajectory guide frame includes one of a groove and a projection and the bracket includes the other of the groove and the projection, and the projection is cooperatively seated in the groove to permit rotation of the bracket with respect to the trajectory axis while preventing axial translation of the bracket along the trajectory axis. The groove may be configured to limit rotation of the bracket with respect to the trajectory axis to a prescribed range of rotation.

In some embodiments, the bracket and the trajectory guide frame are configured to permit the bracket to be alternatively mounted on each of two opposed sides of the targeting cannula.

The bracket may be configured to removably snap fit onto the trajectory guide frame.

The system can include a locking device to secure the light transmission scope to the bracket.

According to some embodiments, the system includes the light transmission scope and the light transmission scope is a fiber scope.

According to embodiments of the present invention, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a yoke and a targeting cannula. The base has a patient access aperture therein. The base is configured to be secured to the body of the patient. The yoke is mountable on the base in a prescribe orientation with respect to the base. The targeting cannula is mounted on the yoke for movement therewith relative to the base. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. First and second spaced apart pivot holes are provided in one of the base and the yoke and first and second pivot pins are associated with the other of the base and the yoke. The yoke is configured to be mounted on the base in the prescribed orientation with the first pivot pin received in the first pivot hole and the second pivot pin received in the second pivot hole, whereby the yoke is pivotable relative to the base about the first and second pivot pins about a roll axis. The first and second holes are relatively configured to prevent operative engagement between the first pivot pin and the second pivot hole to inhibit pivotal mounting of the yoke on the base in an orientation other than the prescribed orientation.

The first pivot pin may have a greater diameter than the second pivot pin and the second pivot hole.

In some embodiments, at least one of the first and second pivot pins is adjustable to selectively change a length of said adjustable pivot pin extending toward its associated one of the first and second pivot holes.

In some embodiments, the first and second pivot holes are located in the base, and the base includes a pair of spaced apart mount arms each having a guide slot therein extending to a respective one of the first and second guide holes to receive and guide the first and second pivot pins to the first and second pivot holes. According to some embodiments, the first and second pivot pins are located on first and second yoke mount arms, respectively, and the base is configured to elastically deflect the first and second yoke mount arms apart as the first and second pivot pins are slid down the guide slots to the first and second pivot holes to mount the yoke on the base.

The first and second pivot pins can be releasably spring loaded into engagement with the first and second pivot holes to permit the yoke to be selectively dismounted from the base.

According to embodiments of the present invention, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a platform, a targeting cannula, and a stabilizer mechanism. The base has a patient access aperture therein. The base is configured to be secured to the body of the patient. The platform is mounted on the base and includes a support table and a moving plate that is movable relative to the support table and the base. The targeting cannula is mounted on the moving plate for movement therewith relative to the support table and the base. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. The stabilizer mechanism is operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base.

The trajectory guide frame may further include a yoke movably mounted on the base and rotatable relative to the base about a pivot axis. The platform is mounted on the yoke for rotation therewith and the platform is configured to permit translational movement of the moving plate with respect to the yoke.

In some embodiments, the stabilizer mechanism includes an adjustment device and a rub bar, and the rub bar and the support table cooperatively define a slot through which the moving plate slides in contact with the rub bar. The adjustment device may be operable to apply a load to the rub bar to compressively load the moving plate in the slot between the support table and the rub bar. The loading device can include at least one screw.

According to embodiments of the present invention, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a platform, a targeting cannula and a lock clip. The base has a patient access aperture therein. The base is configured to be secured to the body of the patient. The platform is mounted on the base and includes a support table and a moving plate that is movable relative to the support table and the base. The targeting cannula is mounted on the moving plate for movement therewith relative to the support table and the base. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. The lock clip is mounted on the platform and configured, when in a locking position, to prevent relative movement between the support table and the moving plate. The lock clip is removable to permit relative movement between the support table and the moving plate.

The trajectory guide frame may include a first lock hole in the support table and a second lock hole in the moving plate. The lock clip extends through the first and second holes when in the locking position.

According to some embodiments, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a targeting cannula and an MRI-visible fiducial marker. The base has a patient access aperture therein. The base is configured to be secured to the body of the patient. The base defines a fiducial cavity and a tab aperture communicating with a fiducial cavity. The targeting cannula is mounted on the base for movement relative thereto. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. The MRI-visible fiducial marker is mounted on the base and includes a body portion containing an MRI-visible material and a fill tab extending from the body portion. At least a portion of the body portion is disposed in the fiducial cavity and the fill tab extends through the tab aperture.

According to some embodiments, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a targeting cannula and an MRI-visible fiducial marker. The base has a patient access aperture therein. The base is configured to be secured to the body of a patient. The base includes a fiducial mount structure and a fiducial locator feature associated with the fiducial mount structure. The targeting cannula is mounted on the base for movement relative thereto. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. The MRI-visible fiducial marker is mounted on the fiducial mount structure. The MRI-visible fiducial marker is toroidal and defines a central opening. The fiducial marker extends into the central opening to positively locate the MRI-visible fiducial marker with respect to the base.

According to some embodiments, a trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure includes a base, a targeting cannula and a plurality of MRI-visible fiducial markers. The base has a patient access aperture therein. The base is configured to be secured to the body of a patient. The targeting cannula is mounted on the base for movement relative thereto. The targeting cannula includes a guide bore therethrough that is configured to guide placement of the interventional device in vivo. The plurality of MRI-visible fiducial markers are mounted on the base. The MRI-visible fiducial markers are relatively positioned in an asymmetric layout to facilitate positive determination of an orientation of the base in free space from an MR image.

In some embodiments, the plurality of MRI-visible fiducial markers includes at least first, second and third MRI-visible fiducial markers each located on a circle, and a circumferential spacing between the first and second MRI-visible fiducial markers is less than a circumferential spacing between the first and third MRI-visible fiducial markers.

Further features, advantages and details of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiments that follow, such description being merely illustrative of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of an MRI-guided interventional system, according to some embodiments of the present invention.

FIG. 1B illustrates a user interface that displays, and that allows a user to adjust, the trajectory of a targeting cannula, according to some embodiments of the present invention.

FIG. 2A is a top perspective view of a burr hole formed in the skull of a patient, and a burr hole ring overlying the burr hole and secured to the skull.

FIG. 2B is a top perspective view of a removable centering device positioned on the burr hole ring of FIG. 1.

FIG. 3A is a perspective view of a trajectory frame utilized in the MRI-guided interventional system, according to some embodiments of the present invention.

FIGS. 3B-3E are side view, schematic illustrations of the trajectory frame being secured to the skull of a patient.

FIGS. 4-5 are partial perspective views of the frame of FIG. 3A illustrating the base of the frame being positioned on the skull of a patient with the centering device of FIG. 2B extending through the patient access aperture.

FIG. 6 illustrates the base secured to the skull of a patient.

FIG. 7 is an enlarged partial perspective view of the base illustrating an attachment location with a pair of adjacent apertures for receiving fasteners therethrough, according to some embodiments of the present invention.

FIG. 8A is a perspective view of the frame of FIG. 3A secured to the body (e.g., skull) of a patient, and with the targeting cannula in an extended position.

FIG. 8B is a cut-away perspective view of the frame of FIG. 3A, illustrating a targeting cannula according to some embodiments of the present invention.

FIGS. 9 and 10A-10C illustrate a remote control unit for remotely controlling the positioning actuators of the frame of FIG. 3A, according to some embodiments of the present invention.

FIG. 11 is a perspective view of the base of the frame of FIG. 3A illustrating fiducial markers associated therewith and illustrating an arcuate arm with a thread pattern formed in a surface thereof that is configured to be engaged by a roll axis actuator, according to some embodiments of the present invention.

FIG. 12 is a partial perspective view of the frame of FIG. 3A illustrating a yoke arcuate arm with a thread pattern formed in a surface thereof that is configured to be engaged by a pitch axis actuator, according to some embodiments of the present invention.

FIGS. 13A-13B illustrate an optic fiber scope for a video imaging camera mounted to the frame of FIG. 3A so as to view a burr hole, according to some embodiments of the present invention.

FIG. 14 is an enlarged, partial perspective view of the frame of FIG. 3A illustrating the targeting cannula locked in an extended position, according to some embodiments of the present invention.

FIG. 15 is an enlarged, partial perspective view of the frame of FIG. 3A illustrating control cables removably engaged with respective actuators, and illustrating flexible elastomeric collars configured to surround respective actuator free ends and to maintain engagement of the cable ends to a respective actuator free end, according to some embodiments of the present invention.

FIG. 16A is a partial perspective view of a frame of an MRI-guided interventional system, according to other embodiments of the present invention, and illustrating actuators positioned on a side of the frame and illustrating control cables removably engaged with the respective actuators.

FIG. 16B is a partial perspective view of an exemplary prototype actuator illustrating a remote control cable end about to be inserted into a slot in the actuator free end, according to some embodiments of the present invention.

FIG. 16C is a partial perspective view of the actuator of FIG. 16B with the remote control cable end inserted into the actuator and with an elastomeric collar engaging the free end of the actuator to prevent the cable from being inadvertently removed from the actuator.

FIGS. 16D-16E are partial perspective views of the actuator of FIG. 16C illustrating removal of the elastomeric collar and cable (FIG. 16E) from the free end of the actuator.

FIG. 17 illustrates the frame of FIG. 3A secured to the skull of a patient and illustrates a desired trajectory for an interventional device, and also illustrates the actual trajectory of the interventional device as oriented by the frame.

FIG. 18 illustrates the frame of FIG. 17 after reorientation via manipulation of one or more frame actuators such that the actual trajectory is adjusted to be in alignment with the desired trajectory.

FIG. 19A is an enlarged, partial perspective view of the frame of FIG. 3A illustrating the X-Y support table, according to some embodiments of the present invention.

FIG. 19B schematically illustrates X-Y translation of an X-Y support table and rotational movement of the yoke and platform, according to some embodiments of the present invention.

FIG. 19C is partial perspective view of an X-Y support table, according to some embodiments, with elements removed to reveal internal components of an X-direction actuator and Y-direction actuator.

FIG. 20 illustrates a depth stop with a peel-away sheath inserted therein, according to some embodiments of the present invention.

FIG. 21 illustrates an imaging probe inserted within the peel-away sheath of FIG. 20 and with the depth stop advanced to a depth mark on the peel-away sheath, according to some embodiments of the present invention.

FIG. 22 illustrates the depth stop and probe being inserted into the targeting cannula of the frame of FIG. 3A.

FIG. 23 illustrates the probe of FIG. 22 being removed from the peel-away sheath and depth stop.

FIG. 24 illustrates a lead lock secured to the depth stop of FIG. 23.

FIG. 25 illustrates a lead being inserted through the lead lock of FIG. 24 and through the targeting cannula.

FIG. 26A is a perspective view of the frame of FIG. 3A with the lead of FIG. 25 inserted into the brain of a patient and with the peel-away sheath being removed, according to some embodiments of the present invention.

FIG. 26B is an enlarged view of the distal end of the peel-away sheath with the distal end of the lead extending therethrough, prior to removal of the sheath.

FIG. 27 illustrates a clamp inserted within and attached to the burr hole ring that is configured to prevent the lead from being retracted from the brain as the frame is removed from the skull of the patient.

FIGS. 28A-28G are side view, schematic illustrations of the trajectory frame illustrating exemplary operation of the device for the insertion of interventional devices within the body of a patient via the targeting cannula.

FIG. 29 illustrates a drape configured to be positioned adjacent to a patient and that has a pocket configured to removably receive the remote control unit of FIGS. 9 and 10A-10C.

FIG. 30 illustrates a safety lanyard according to some embodiments of the present invention, wherein the safety lanyard is attached to the remote control unit of FIGS. 9 and 10A-10C and to a rigid object to prevent inadvertent detachment of the control cables.

FIG. 31 is a schematic illustration of a patient positioned within an MRI scanner and a user utilizing a remote control apparatus 400 and display monitors to position a targeting cannula, according to some embodiments of the present invention.

FIGS. 32A-32C illustrate a remote control unit for remotely controlling the positioning actuators of the frame of FIG. 3A, according to other embodiments of the present invention.

FIG. 33 is a perspective view of a trajectory guide frame and a camera bracket according to further embodiments of the present invention.

FIG. 34 is a top plan view of the trajectory guide frame of FIG. 33 with a yoke and platform thereof removed and the camera bracket shown mounted thereon in alternative positions.

FIG. 35 is a partial perspective view of the trajectory guide frame and camera bracket of FIG. 33.

FIG. 36 is an exploded, partial perspective view of the trajectory guide frame and camera bracket of FIG. 33.

FIG. 37 is a cross-sectional view of the trajectory guide frame and camera bracket of FIG. 33 taken along the line 37-37 of FIG. 35.

FIG. 38 is a cross-sectional view of the trajectory guide frame and camera bracket of FIG. 33 taken along the line 38-38 of FIG. 33, wherein a targeting cannula thereof is in a retracted position.

FIG. 39 is a partial top plan view of the trajectory guide frame of FIG. 33.

FIG. 40 is a partial cross-sectional view of the trajectory guide frame of FIG. 33, wherein the targeting cannula is in an extended position.

FIG. 41 is a partial cross-sectional view of the trajectory guide frame of FIG. 33, wherein an alternative targeting cannula according to further embodiments of the present invention is in a retracted position.

FIGS. 42 and 43 are exploded perspective views of a base and a yoke of the trajectory guide frame of FIG. 33 illustrating a mounting system according to some embodiments of the present invention.

FIG. 44 is a cross-sectional view of the base and yoke of FIG. 42 taken along the line 44-44 of FIG. 43.

FIG. 45 is a partial perspective view of the trajectory guide frame of FIG. 33 illustrating a stabilizer system according to some embodiments of the present invention.

FIG. 46 is an exploded, partial perspective view of the trajectory guide frame of FIG. 33.

FIG. 47 is a further perspective view of the trajectory guide frame of FIG. 33.

FIG. 48 is a perspective view of a lock clip for use with the trajectory guide frame of FIG. 33.

FIG. 49A is a top plan view of the base of the trajectory guide frame of FIG. 33 illustrating a layout of MRI-visible fiducial markers of the trajectory guide frame.

FIG. 49B is a schematic view of a display including an image based on MRI image data including representations of a patient's head and a base and fiducial markers of the trajectory guide frame.

FIG. 50 is an enlarged, fragmentary, perspective view of the trajectory guide frame of FIG. 33 illustrating a fiducial marker positioning feature according to some embodiments of the present invention.

FIG. 51 is an enlarged, fragmentary, perspective view of the trajectory guide frame of FIG. 33 illustrating a fiducial marker tab relief feature according to some embodiments of the present invention.

FIG. 52 is a fragmentary, perspective view of an MRI-guided interventional system according to embodiments of the present invention including a pair of the trajectory guide frames of FIG. 33 mounted on a patient's head to conduct a bilateral surgical procedure on the patient.

DETAILED DESCRIPTION

The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which some embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising.” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of “over” and “under”. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

The term “MRI visible” means that a device is visible, directly or indirectly, in an MRI image. The visibility may be indicated by the increased SNR of the MRI signal proximate to the device (the device can act as an MRI receive antenna to collect signal from local tissue) and/or that the device actually generates MRI signal itself, such as via suitable hydro-based coatings and/or fluid (typically aqueous solutions) filled channels or lumens.

The term “MRI compatible” means that a device is safe for use in an MRI environment and/or can operate as intended in an MRI environment, and, as such, if residing within the high-field strength region of the magnetic field, is typically made of a non-ferromagnetic MRI compatible material(s) suitable to reside and/or operate in a high magnetic field environment.

The term “high-magnetic field” refers to field strengths above about 0.5 T, typically above 1.0T, and more typically between about 1.5T and 10T.

The term “targeting cannula” refers to an elongate device, typically having a substantially tubular body that can be oriented to provide positional data relevant to a target treatment site and/or define a desired access path orientation or trajectory. At least portions of a targeting cannula contemplated by embodiments of the invention can be configured to be visible in an MRI image, thereby allowing a clinician to visualize the location and orientation of the targeting cannula in vivo relative to fiducial and/or internal tissue landscape features. Thus, the term “cannula” refers to an elongate device that can be associated with a trajectory frame that attaches to a patient, but does not necessarily enter the body of a patient.

The term “imaging coils” refers to a device that is configured to operate as an MRI receive antenna. The term “coil” with respect to imaging coils is not limited to a coil shape but is used generically to refer to MRI antenna configurations, loopless, looped, etc., as are known to those of skill in the art. The term “fluid-filled” means that the component includes an amount of the fluid but does not require that the fluid totally, or even substantially, fill the component or a space associated with the component. The fluid may be an aqueous solution, MR contrast agent, or any material that generates MRI signal.

The term “two degrees of freedom” means that the trajectory frame described herein allows for at least translational (swivel or tilt) and rotational movement over a fixed site, which may be referred to as a Remote Center of Motion (RCM).

The term “programmatically” refers to operations directed and/or primarily carried out electronically by computer program modules, code and instructions.

The term “fiducial marker” refers to a marker that can be identified using electronic image recognition, electronic interrogation of MRI image data, or three-dimensional electrical signals to define a position and/or find the feature or component in 3-D space.

Embodiments of the present invention can be configured to guide and/or place diagnostic or interventional devices and/or therapies to any desired internal region of the body or object using MRI and/or in an MRI scanner or MRI interventional suite. The object can be any object, and may be particularly suitable for animal and/or human subjects. Some embodiments can be sized and configured to place implantable DBS leads for brain stimulation, typically deep brain stimulation. Some embodiments can be configured to deliver tools or therapies that stimulate a desired region of the sympathetic nerve chain. Other uses inside or outside the brain include stem cell placement, gene therapy or drug delivery for treating physiological conditions. Some embodiments can be used to treat tumors. Some embodiments can be used for RF ablation, laser ablation, cryogenic ablation, etc. In some embodiments the trajectory frame and/or interventional tools can be configured to facilitate high resolution imaging via integral intrabody imaging coils (receive antennas), and/or the interventional tools can be configured to stimulate local tissue, which can facilitate confirmation of proper location by generating a physiologic feedback (observed physical reaction or via fMRI).

Some embodiments can be used to deliver bions, stem cells or other target cells to site-specific regions in the body, such as neurological target and the like. In some embodiments, the systems deliver stem cells and/or other cardio-rebuilding cells or products into cardiac tissue, such as a heart wall via a minimally invasive MRI guided procedure, while the heart is beating (i.e., not requiring a non-beating heart with the patient on a heart-lung machine). Examples of known stimulation treatments and/or target body regions are described in U.S. Pat. Nos. 6,708,064; 6,438,423; 6,356,786; 6,526,318; 6,405,079; 6,167,311; 6,539,263; 6,609,030 and 6,050,992, the contents of which are hereby incorporated by reference as if recited in full herein.

Generally stated, some embodiments of the invention are directed to MRI interventional procedures and provide interventional tools and/or therapies that may be used to locally place interventional tools or therapies in vivo to site-specific regions using an MRI system. The interventional tools can be used to define an MRI-guided trajectory or access path to an in vivo treatment site. Some embodiments of the invention provide interventional tools that can provide positional data regarding location and orientation of a tool in 3-D space with a visual confirmation on an MRI. Embodiments of the invention may provide an integrated system that may allow physicians to place interventional devices/leads and/or therapies accurately and in shorter duration procedures over conventional systems (typically under six hours for DBS implantation procedures, such as between about 1-5 hours).

In some embodiments, MRI can be used to visualize (and/or locate) a therapeutic region of interest inside the brain or other body locations and utilize MRI to visualize (and/or locate) an interventional tool or tools that will be used to deliver therapy and/or to place a chronically implanted device that will deliver therapy. Then, using the three-dimensional data produced by the MRI system regarding the location of the therapeutic region of interest and the location of the interventional tool, the system and/or physician can make positional adjustments to the interventional tool so as to align the trajectory of the interventional tool, so that when inserted into the body, the interventional tool will intersect with the therapeutic region of interest. With the interventional tool now aligned with the therapeutic region of interest, an interventional probe can be advanced, such as through an open lumen inside of the interventional tool, so that the interventional probe follows the trajectory of the interventional tool and proceeds to the therapeutic region of interest. It should be noted that the interventional tool and the interventional probe may be part of the same component or structure. A sheath may optionally form the interventional tool or be used with an interventional probe or tool.

In particular embodiments, using the MRI in combination with local or internal imaging coils and/or MRI contrast material that may be contained at least partially in and/or on the interventional probe or sheath, the location of the interventional probe within the therapeutic region of interest can be visualized on a display or image and allow the physician to either confirm that the probe is properly placed for delivery of the therapy (and/or placement of the implantable device that will deliver the therapy) or determine that the probe is in the incorrect or a non-optimal location. Assuming that the interventional probe is in the proper desired location, the therapy can be delivered and/or the interventional probe can be removed and replaced with a permanently implanted therapeutic device at the same location.

In some embodiments, in the event that the physician determines from the MRI image produced by the MRI and the imaging coils, which may optionally be contained in or on the interventional probe, that the interventional probe is not in the proper location, a new therapeutic target region can be determined from the MRI images, and the system can be updated to note the coordinates of the new target region. The interventional probe is typically removed (e.g., from the brain) and the interventional tool can be repositioned so that it is aligned with the new target area. The interventional probe can be reinserted on a trajectory to intersect with the new target region. Although described and illustrated herein with respect to the brain and the insertion of deep brain stimulation leads, it is understood that embodiments of the present invention may be utilized at other portions of the body and for various other types of procedures.

Exemplary embodiments are described below with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the functions/acts specified in the block diagrams and/or flowchart block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, exemplary embodiments may be implemented in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, exemplary embodiments may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CD-ROM). Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

Computer program code for carrying out operations of data processing systems discussed herein may be written in a high-level programming language, such as Java, AJAX (Asynchronous JavaScript), C, and/or C++, for development convenience. In addition, computer program code for carrying out operations of exemplary embodiments may also be written in other programming languages, such as, but not limited to, interpreted languages. Some modules or routines may be written in assembly language or even micro-code to enhance performance and/or memory usage. However, embodiments are not limited to a particular programming language. It will be further appreciated that the functionality of any or all of the program modules may also be implemented using discrete hardware components, one or more application specific integrated circuits (ASICs), or a programmed digital signal processor or microcontroller.

Embodiments of the present invention will now be described in detail below with reference to the figures. FIG. 1A is a block diagram of an MRI-guided interventional system 50, according to some embodiments of the present invention. The illustrated system 50 includes an MRI scanner 75, a trajectory frame 100 attached to the body of a patient positioned within a magnetic field of the MRI scanner 75, a remote control unit 400, a trajectory guide software module 300, and a clinician display 500. The trajectory frame 100 supports a targeting cannula through which various interventional devices may be inserted into the body of a patient. The frame 100 is adjustable such that the targeting cannula is rotatable about a pitch axis, about a roll axis, and such that the targeting cannula can translate in X-Y directions. The frame 100 may be attached to the body of a patient directly or indirectly and may be configured to be attached to various parts of the body.

In some embodiments, a remote control unit 400 is provided to allow a user to remotely adjust the position of the targeting cannula. The trajectory guide software module 300 allows a user to define and visualize, via display 500, a desired trajectory (D, FIGS. 17-18) into the body of a patient of an interventional device extending through the targeting cannula. The trajectory guide software module 300 also allows the user to visualize and display, via display 500, an actual trajectory (A, FIG. 17) into the body of an interventional device extending through the targeting cannula. The trajectory guide software module 300 displays to the user the necessary positional adjustments (e.g., pitch axis rotation, roll axis rotation, X-Y translation) needed to align the actual trajectory of the targeting cannula with the desired trajectory path (FIG. 1B). In addition, the user can view, via display 500, the actual trajectory changing as he/she adjusts the position of the targeting cannula. The trajectory guide software module 300 is configured to indicate and display when an actual trajectory is aligned with a desired trajectory.

FIG. 2A illustrates a burr hole 10 formed in the skull S of a patient. A burr hole ring 12 overlies the burr hole 10 and is secured to the skull S. The illustrated burr hole ring 12 has a pair of ears 14, each configured to receive a respective fastener (e.g., screw) therethrough for securing the burr hole ring 12 to the skull. In the illustrated embodiment, the burr hole ring 12 is secured to the skull S via screws 16. FIG. 2B illustrates a removable centering device 18 positioned on the burr hole ring 12. The centering device 18 includes cut out portions 20 that fit over the ears 14 of the burr hole ring 12. The function of the centering device 18 is to facilitate centering a trajectory frame 100, described below, over the burr hole 10. After the frame 100 is attached to the skull of a patient, the centering device 18 is removed.

Referring to FIG. 3A, a trajectory frame 100 with a targeting cannula 200 associated therewith is illustrated. The trajectory frame 100 allows for the adjustability (typically at least two degrees of freedom, including rotational and translational) and calibration/fixation of the trajectory of the targeting cannula 200 and/or probe or tool inserted through the targeting cannula 200. The targeting cannula 200 includes an axially-extending guide bore (not shown) therethrough that is configured to guide the desired therapeutic or diagnostic tool, e.g., intra-brain placement of a stimulation lead (or other type of device) in vivo, as will be described below. Intra-brain placement of devices may include chronically placed devices and acutely placed devices. The trajectory frame 100 may include fiducial markers 117 that can be detected in an MRI to facilitate registration of position in an image.

The illustrated trajectory frame 100 is configured to be mounted to a patient's skull around a burr hole ring (12, FIG. 1) and over a burr hole (10, FIG. 1), to provide a stable platform for advancing surgical devices, leads, etc. in the brain. The frame 100 includes a base 110, a yoke, 120, a platform 130, and a plurality of actuators 140 a-140 d. The base 110 has a patient access aperture 112 formed therein, as illustrated. The base 110 is configured to be secured (directly or indirectly) to the skull of a patient such that the patient access aperture 112 overlies the burr hole 10 in the patient skull. The patient access aperture 112 is centered over the burr hole 10 via the removable centering device 18. The yoke 120 is movably mounted to the base 110 and is rotatable about a roll axis RA. A roll actuator 140 a is operably connected to the yoke 120 and is configured to rotate the yoke 120 about the roll axis RA, as will be described in detail below. In some embodiments, the yoke 120 has a range of motion about the roll axis RA of about seventy degrees (70°). However, other ranges, greater and lesser than 70°, are possible, e.g., any suitable angle typically between about 10°-90°, 30°-90°, etc. The illustrated platform 130 is movably mounted to the yoke 120 and is rotatable about a pitch axis PA. In some embodiments, the platform 130 has a range of motion about the pitch axis PA of about seventy degrees (70°). However, other ranges, greater and lesser than 70°, are possible, e.g., any suitable angle typically between about 10°-90°, 30°-90°, etc.

FIGS. 3B-3E are side view, schematic illustrations of the trajectory frame being secured to the skull of a patient. FIG. 3B illustrates use of the centering device 18 to align the frame 100 relative to the burr hole 10. In FIG. 3C, the frame 100 is secured to the skull with fasteners and such that the patient access aperture 112 in the base 110 is centered around the centering device 18. In FIG. 3D, the yoke 120 is rotated out of the way such that the centering device 18 can be removed. In FIG. 3E, the targeting cannula 200 is moved to an extended position and locked in the extended position via prongs 208.

The platform 130 includes an X-Y support table 132 that is movably mounted to the platform 130. The X-Y support table 132 is configured to move in an X-direction and Y-direction relative to the platform 130. An X-direction actuator 140 c is operably connected to the platform 130 and is configured to move the X-Y support table 132 in the X-direction. A Y-direction actuator 140 d is operably connected to the platform 130 and is configured to move the X-Y support table 132 in the Y-direction. A pitch actuator 140 b is operably connected to the platform 130 and is configured to rotate the platform 130 about the pitch axis PA, as will be described in detail below.

The actuators 140 a-140 d are configured to translate and/or rotate the frame. The targeting cannula 200 is configured to translate in response to translational movement of the X-Y support table 132 and to rotate in response to rotational movement of the yoke 120 and platform 130 to define different axial intrabody trajectories extending through the patient access aperture 112 in the frame base 110.

The actuators 140 a-140 d may be manually-operated devices, such as thumbscrews, in some embodiments. The thumbscrews can be mounted on the frame 100 or may reside remotely from the frame 100. A user may turn the actuators 140 a-140 d by hand to adjust the position of the frame 100 and, thereby, a trajectory of the targeting cannula 200. In other embodiments, the actuators 140 a-140 d are operably connected to a remote control unit 400 (FIGS. 9-10) via a respective plurality of non-ferromagnetic, flexible drive shafts or control cables 150 a-150 d. The remote control unit 400 includes a plurality of position controls 402 a-402 d, and each cable 150 a-150 d is operably connected to a respective position control 402 a-402 d and to a respective actuator 140 a-140 d. Movement of a position control 402 a-402 d operates a respective actuator 140 a-140 d via a respective control cable 150 a-150 d, as will be described below. The cables 150 a-150 d may extend a suitable distance (e.g., between about 1-4 feet, etc.) to allow a clinician to adjust the settings on the trajectory frame 100 without moving a patient and from a position outside the bore of a magnet (where such magnet type is used) associated with an MRI scanner.

Referring to FIGS. 6-7, the base 110 includes a plurality of locations 112 for attaching the base 110 to a skull of a patient via fasteners. Each location may include two or more adjacent apertures 114. Each aperture 114 is configured to receive a fastener (e.g., a screw, rod, pin, etc.) therethrough that is configured to secure the base 110 to the skull of a patient.

The base 110 also includes MRI-visible fiducial markers 117 that allow the location/orientation of the frame 100 to be determined within an MRI image during an MRI-guided procedure. In the illustrated embodiment, the fiducial markers 117 have a torus or “doughnut” shape and are spaced apart. However, fiducial markers having various shapes and positioned at various locations on the frame 100 may be utilized.

The base 110 also includes a pair of spaced apart arcuate arms 116, as illustrated in FIG. 11. The yoke 120 is pivotally attached to pivot points 113 for rotation about the roll axis RA. The yoke 120 engages and moves along the base arcuate arms 116 when rotated about the roll axis RA. In the illustrated embodiment, one of the base arcuate arms 116 includes a thread pattern 118 formed in (e.g., embossed within, machined within, etc.) a surface 116 a thereof. However, in other embodiments, both arms 116 may include respective thread patterns. The roll actuator 140 a includes a rotatable worm 142 with teeth that are configured to engage the thread pattern 118, as illustrated in FIG. 5. As the worm 142 is rotated, the teeth travel along the thread pattern 118 in the arcuate arm surface 116 a. Because the base 110 is fixed to a patient's skull, rotation of the roll actuator worm 142 causes the yoke 120 to rotate about the roll axis RA relative to the fixed base 110. Rotation about roll axis RA is illustrated in FIGS. 4-5. For example, in FIG. 5, the yoke 120 is rotated about the roll axis RA sufficiently to allow removal of the centering device 18.

Referring to FIG. 12, the yoke 120 includes a pair of spaced apart upwardly extending, arcuate arms 122. The platform 130 engages and moves along the yoke arcuate arms 122 when rotated about the pitch axis PA. In the illustrated embodiment, one of the yoke arcuate arms 122 includes a thread pattern 124 formed in (e.g., embossed within, machined within, etc.) a surface 122 a thereof. However, in other embodiments, both arms 122 may include respective thread patterns. The pitch actuator 140 b includes a rotatable worm 146 with teeth 148 that are configured to engage the thread pattern 124. As the worm 146 is rotated, the teeth 148 travel along the thread pattern 124 in the arcuate arm surface 122 a. Because the base 110 is fixed to a patient's skull, rotation of the pitch actuator worm 146 causes the platform 130 to rotate about the pitch axis PA relative to the fixed base 110.

As illustrated in FIG. 19A, the X-Y support table 132 includes a moving plate 134 that moves in both the X-direction and Y-direction. The X-direction actuator 140 c, when rotated, causes translational movement of the moving plate 134 along the X-axis. For example, clockwise rotation of the X-direction actuator 140 c causes movement toward the “−X direction (i.e., to the left) in FIG. 19A; and counterclockwise rotation of the X-direction actuator 140 c causes movement along the +X direction (i.e., to the right) in FIG. 19A, etc. The Y-direction actuator 140 d, when rotated, causes translational movement of the moving plate 134 along the Y-axis. For example, clockwise rotation of the Y-direction actuator 140 d causes movement along the −Y direction (i.e., out of the paper) in FIG. 19A; and clockwise rotation of the Y-direction actuator 140 d causes movement along the +Y direction (i.e., into the paper) in FIG. 19A. In the illustrated embodiment, graduation scales 136, 137 are provided on the platform adjacent the moving plate 134. The moving plate 134 includes a pair of marks or indicators 138 that provide visual indication of X-Y movement of the moving plate 134. FIG. 19B illustrates X-Y translation of an X-Y support table 132, according to some embodiments of the present invention.

Various internal drive mechanisms may be utilized for causing translational movement of the moving plate 134 in response to user rotation of the X-direction actuator 140 c and the Y-direction actuator 140 d. For example, drive belts, linkages, gears, or worm drives may be utilized, as would be understood by one skilled in the art of X-Y tables. Embodiments of the present invention are not limited to any particular mechanism for translating the X-Y table 132 along the X and Y directions. FIG. 19C is partial perspective view of an X-Y support table, according to some embodiments, with elements removed to reveal internal components of an X-direction actuator 140 c and Y-direction actuator 140 d.

As illustrated in FIG. 3A, the roll actuator 140 a, pitch actuator 140 b, X-direction actuator 140 c, and Y-direction actuator 140 d each extend outwardly from the frame 100 along the same direction (e.g., upwardly from the platform 130). This configuration facilitates easy connection of the control cables 150 a-150 d to the actuators 140 a-140 d (where used) and also facilitates bundling of the cables 150 a-150 d to reduce clutter or provide ease of handling and set-up. Embodiments of the present invention are not limited to the illustrated embodiment, however. The actuators 140 a-140 d may extend in various directions and these directions may be different from each other. In addition, the actuators 140 a-140 d may extend along the same direction from the frame, but in a different direction than that illustrated in FIG. 3A. For example, FIG. 16 illustrates an embodiment where the actuators 140 a-140 d extend from a common side of the platform 130.

Referring to FIGS. 9 and 10A-10C, the remote control unit 400 of the illustrated system 50 includes a plurality of manually-operable position controls 402 a-402 d. Specifically, the control unit 400 includes a roll adjustment control 402 a, a pitch adjustment control 402 b, an X-direction adjustment control 402 c, and a Y-direction adjustment control 402 d. A roll control cable 150 a is operably connected to the roll adjustment control 402 a and to the roll actuator 140 a such that movement of the roll adjustment control 402 a operates the roll actuator 140 a via the roll control cable 150 a. A pitch control cable 150 b is operably connected to the pitch adjustment control 402 b and to the pitch actuator 140 b such that movement of the pitch adjustment control 402 b operates the pitch actuator 140 b via the pitch control cable 150 b. An X-direction control cable 150 c is operably connected to the X-direction control 402 c and to the X-direction actuator 140 c such that movement of the X-direction adjustment control 402 c operates the X-direction actuator 140 c via the X-direction control cable 150 c. A Y-direction control cable 150 d is operably connected to the Y-direction control 402 d and to the Y-direction actuator 140 d such that movement of the Y-direction adjustment control 402 d operates the Y-direction actuator 140 d via the Y-direction control cable 150 d.

In the illustrated embodiment, each of the position controls 402 a-402 d is a thumbwheel control that can be rotated by a user's finger in clockwise and counterclockwise directions. Rotation of each thumbwheel 402 a-402 d by a user causes corresponding axial rotation of a respective control cable 150 a-150 d and corresponding axial rotation of a respective actuator 140 a-140 d.

FIG. 10B illustrates position controls, according to additional embodiments of the present invention, that utilize two thumbwheels. One thumbwheel 402 a′ is for “fine” adjustments; the other thumbwheel 402 a″ is for “gross” adjustments. The amount of fine and gross adjustment is correlated to the diameter of each thumbwheel, as would be understood by one skilled in the art. FIG. 10C illustrates a position control 402 a′″, according to additional embodiments of the present invention, that indicates incremental X-Y variable markings.

In the illustrated embodiment, locking mechanisms 404 a-404 c are associated with the thumbwheels 402 a-402 d and prevent user rotation thereof when in a locked position. For example, a locking mechanism 404 a is operably associated with the roll adjustment control 402 a and is configured to prevent rotation thereof by a user when in a “locked” position. Locking mechanism 404 b is operably associated with pitch adjustment control 402 b and is configured to prevent rotation thereof by a user when in a “locked” position. Locking mechanism 404 c is operably associated with X-direction control 402 c and Y-direction control 402 d and is configured to prevent rotation of X-direction control 402 c and Y-direction control 402 d by a user when in a “locked” position.

Each control cable 150 a-150 d can have a geometrically shaped rigid end 151 a-151 d that is configured to removably engage a free end of a respective actuator 140 a-140 d. As illustrated in FIG. 16, the respective free ends 141 a-141 d of the actuators 140 a-140 d may have a slot 143 formed therein that is configured to removably receive a respective cable end. Exemplary cable end shapes include, but are not limited to, “L” shapes, “U” shapes, square shapes, rectangular shapes, oval/circular shapes, and other polygonal shapes. Each cable end has sufficient rigidity such that axial rotation of the cable causes the cable free end to impart rotational motion to a respective actuator. FIG. 15 illustrates the free end of cable 150 b having a connector 151 b with a geometric shape attached thereto that is configured to matingly engage a respective slot 143 in actuator 140 b, according to other embodiments of the present invention.

In some embodiments, the free end of an actuator 140 a-140 d may be configured to receive only a specific one of the control cables 150 a-150 d. For example, in FIG. 15, the connector 151 b may not fit within the slots 143 of any of the other actuators. As such, a control cable cannot be inadvertently connected to the wrong actuator. For example, the roll adjustment actuator free end 141 a may be configured to only receive the free end 151 a of the control cable 150 a associated with the roll control 402 a. Similarly, the pitch adjustment actuator free end 141 b may be configured to only receive the free end 151 b of the control cable 150 b associated with the pitch control 402 b.

Each control cable 150 a-150 d also has a flexible elastomeric (e.g., silicone, rubber, etc.) collar 154 a-154 d that is configured to surround a respective actuator 140 a-140 d and maintain engagement of the respective cable end 151 a-151 d within the respective actuator. Each elastomeric collar 154 a-154 d is configured to prevent removal of a cable by a user, for example, as a result of inadvertent tugging on the cable by a user, or by movement of the remote control unit 400. Each of the illustrated collars 154 a-154 d can be rolled or folded back then released to cover and conformably compress against an actuator to hold the end of a respective cable in position. Each collar 154 a-154 d can then be pushed back to easily release the cable from the actuator. In the illustrated embodiment, each actuator 140 a-140 d has a circumferential groove 145 configured to receive a corresponding circumferential ridge 156 of a collar 154 a-154 d in mating relation therewith.

FIG. 16B illustrates remote control cable end 151 a about to be inserted into slot 143 in the actuator free end 141 a. The cable end 151 a is inserted into the slot 143 and then the elastomeric collar 154 a is fitted around the actuator 140 a such that the circumferential ridge 156 engages the circumferential actuator groove 145, as illustrated in FIG. 16C. Because of the elastomeric nature of the collar 154 a, the collar snuggly fits the actuator 140 a and retains the cable end 151 a within slot 143. To remove the cable end 151 a, the circumferential ridge 156 is pulled out of the groove 145 and the collar 154 a is rolled back on itself as illustrated in FIGS. 16D-16E.

Embodiments of the present invention are not limited to the illustrated elastomeric collars 154 a-154 d. Other ways of retaining the cable ends 151 a-151 d within respective actuators 140 a-140 d may be utilized without limitation.

In some embodiments, the actuators 140 a-140 d are color coded such that each actuator has a different respective color for easy identification by a user. For example, the roll actuator 140 a may be colored red and the pitch actuator 140 b may be colored yellow such that a user can easily identify the two respective actuators when positioning the frame 100. In some embodiments, the elastomeric collars 154 a-154 d may also be color coded so as to match the color of a respective actuator 140 a-140 d. In some embodiments, the cable ends 151 a-151 d may also be color coded so as to match the color of a respective actuator 140 a-140 d.

In some embodiments of the present invention, the control cables 150 a-150 d are formed of NITINOL or other MR-compatible materials. One or more portions of the frame 100 and the targeting cannula 200 may also be formed of NITINOL or other MR-compatible (non-paramagnetic) materials.

FIG. 31 illustrates a patient positioned within an MRI scanner and a user utilizing the remote control apparatus 400 and display monitors to adjust the trajectory a targeting cannula, according to some embodiments of the present invention.

FIGS. 32A-32C illustrate a remote control unit 800 for remotely controlling the positioning actuators of the frame of FIG. 3A, according to other embodiments of the present invention. The illustrated remote control unit 800 includes a separate, multi-rod control device 802 a-802 d for each respective actuator 140 a-140 d. Each of the control devices 802 a-802 d can be identical in structure and, as such, only one will be described in detail hereinafter. However, each control device 802 a-802 d may be color coded with a color different from the other control devices 802 a-802 d, and each control device 802 a-802 d may have different lengths, shapes or sizes for ease of assembly and/or operation. Moreover, each control device 802 a-802 d may be color coded so as to match the color of a respective actuator 140 a-140 d.

Each control device 802 a-802 d includes a pair of elongated rods 804, 806 (e.g., solid, MRI-compatible rods) joined at respective ends via a flexible member such as a cable 807, as illustrated. The rods 804, 806 may be formed of wood, polymeric material, or other suitable relatively lightweight MM-compatible material. In addition, the rods 804, 806 are not required to be solid.

The cable 807 is relatively short in length relative to the length of rods 804, 806 and serves as a universal joint to allow the two rods 804, 806 to rotate even when oriented transverse to each other. For example, the cable 807 may be between about one quarter inch and about one inch (0.25″-1″) in length. However, embodiments of the present invention are not limited to this range for the length of cable 807; cable 807 may have other lengths. In some embodiments, the cable 807 is an MRI-compatible cable (e.g., NITINOL, etc.). In the illustrated embodiment, the distal end 804 b of rod 804 is joined to the proximal end 806 a of rod 806 via cable 807. The cable 807 may be joined to rods 804, 806 in any of various ways including, but not limited to, via adhesives, via fasteners, via threaded connections, etc.

The proximal end 804 a of rod 804 includes an endcap 808 secured thereto. The endcap 808 may be formed from tactile material to facilitate rotation of rod 804 by a user. A knob or other device that facilitates rotation may be secured to the proximal end of rod 804 in lieu of endcap 808, in other embodiments. In operation, a user rotates the proximal end 804 a of rod 804 in a clockwise or counterclockwise direction to correspondingly rotate actuator 140 a.

The distal end 806 b of rod 806 is joined to actuator 140 a via a flexible member such as a cable 810, as illustrated. The cable 810 is relatively short in length relative to the length of rod 806 and serves as a universal joint to allow rod 806 to rotate even when oriented transverse to actuator 140 a. In some embodiments, the cable 810 is an MRI-compatible cable. For example, the cable 810 may be between about one half inch and about one and one half inch (0.5″-1.5″) in length. However, embodiments of the present invention are not limited to this range for the length of cable 810; cable 810 may have other lengths.

Cable 810 may be joined to rod 806 in any of various ways including, but not limited to, via adhesives, via fasteners, via threaded connections, etc. The free end of cable 810 may have a rigid, geometrical shape, as described above with respect to the embodiments of cables 150 a-150 d, and may be configured to engage a slot within the actuator 140 a, as described above. An elastomeric collar, as described above with respect to FIGS. 16A-16E, may or may not be necessary to retain the free end of cable 810 within actuator 140 a. In the illustrated embodiment, an elastomeric collar is not utilized. When used, an elastomeric collar can also be color coded to the actuator and/or control device rods 804, 806.

In the illustrated embodiment, the control devices 802 a-802 d are supported by a pair of spaced apart separator devices 812. Each separator device 812 includes a plurality of substantially parallel, spaced apart bores passing therethrough that are configured to receive each of the rods 804 for the respective control devices 802 a-802 d. The separator devices 812 are configured to maintain the rods 804 in substantially parallel, spaced apart relationship, as illustrated. In the illustrated embodiment, only rods 804 pass through the two separator devices 812. However, embodiments of the present invention are not limited to the illustrated use, configuration, location, or number of separation devices 812. In addition, although shown as two rods forming each control device 802 a-802 d, they may include three or more spaced apart rods (not shown), or only a single rod (not shown). Moreover, other types of devices may be utilized without limitation.

Referring to FIGS. 14 and 19, an elongated tubular member 204 extends through the platform 130 and yoke 120 and is secured to the X-Y support table 132. The targeting cannula 200 is slidably secured within the tubular member 204 and is movable between extended and retracted positions. FIGS. 3A-3D and 4-6 illustrate the targeting cannula 200 in a retracted position above the burr hole 10 and FIGS. 3E and 8A illustrate the targeting cannula 200 in an extended position. The tubular member 204 is configured to lock the targeting cannula 200 in an extended position and in a retracted position, as illustrated in FIG. 14. The tubular member 204 has a pair of radially opposed elongated, axial-extending slots 206, as illustrated. The ends 206 a, 206 b of each slot 206 include a transverse portion 207 that is configured to retain the targeting cannula 200 in respective extended and retracted positions. The targeting cannula 200 includes a respective pair of radially extending prongs 208, as illustrated. Each prong 208 cooperates with a respective slot 206. When the targeting cannula 200 is moved upwardly to the retracted position, the targeting cannula 200 is rotated slightly (or the tubular member 204 is rotated slightly) such that prongs 208 each engage a respective transverse portion 207. When so engaged, the targeting cannula 200 is retained in the retracted position. When the targeting cannula 200 is moved downwardly to the extended position, the targeting cannula 200 is rotated slightly (or the tubular member 204 is rotated slightly) such that prongs 208 each engage a respective transverse portion 207. When so engaged, the targeting cannula 200 is retained in the extended position.

Embodiments of the present invention are not limited to the illustrated configuration or number of slots 206 in the tubular member 204 or to the number of prongs 208 extending from the targeting cannula 200. For example, the targeting cannula 200 may have a single prong 208 that is configured to cooperate with a respective single slot 206 in the tubular member 204. In addition, slot 206 may have a different configuration than illustrated.

Referring to FIGS. 20-26, a depth stop 210 with a removable sheath 212 inserted and secured therein is illustrated. The illustrated depth stop 210 has a generally cylindrical configuration with opposite proximal and distal ends 210 a, 210 b and is adapted to be removably secured within the proximal end 204 a of the tubular member 204. The depth stop 210 is configured to limit a distance that the sheath 212 extends into the body of a patient when the depth stop is inserted within the tubular member 204. The sheath 212 is configured to receive and guide an elongated interventional device therethrough, as will be described below. The sheath 212 includes opposing tabs 214 a, 214 b that, when pulled apart, cause the sheath 212 to peel away for removal from the targeting cannula 200.

Prior to insertion within the tubular member 204, the distal end 210 b of the depth stop 210 is positioned adjacent to a mark 215 on the removable sheath 212, as illustrated in FIG. 21. Locking screw 216 is then tightened to prevent axial movement of the sheath 212 relative to the depth stop 210. An elongate location verification probe 217, such as an imaging probe or rigid stylet, is then inserted within the sheath 212 as illustrated in FIG. 21.

Referring to FIGS. 22-23, the opposing tabs 214 a, 214 b of the sheath are pulled apart slightly, and the depth stop 210, sheath 212 and imaging probe 217 are inserted into the proximal end 204 a of tubular member 204. When so inserted, as illustrated in FIG. 23, the sheath 212 and imaging probe 217 pass through the axial bore of the targeting cannula 200. The imaging probe 217 is then utilized to verify that the distal end 212 b of the sheath 212 is positioned at the correct location within the body of a patient. Upon verifying that the sheath 212 is accurately positioned, the imaging probe 217 is removed (FIG. 23).

The probe 217 extending through the targeting cannula guide bore can include at least one electrode (which may include a coil winding) on a distal tip portion thereof. The electrode can be a recording and/or stimulating electrode. The electrode can be configured to deliver test voltages for physiologic confirmation of location/efficacy that can be done by fMRI or by feedback from a non-anesthetized patient. Thus, a patient can be stimulated with an interventional probe (the stimulation may be via a transducer on a distal tip portion of the probe), to help confirm that the interventional probe is in the correct location (i.e., confirm proper location via anatomical as well as provide physiologic information and feedback). During (and typically substantially immediately after) stimulation from the interventional probe, the physician can monitor for a physiologic response from the patient that can be observed either directly from the patient as a physical response or via an fMRI-visible response.

The elongate probe 217 can be MRI-visible and may optionally be configured to define an MRI antenna. The system 50 can be configured to allow for real-time tracking under MRI, with an SNR imaging improvement in a diameter of at least 1-10 mm surrounding the probe.

Next, a locking mechanism 220 is removably secured to the proximal end 210 a of the depth stop 210. The locking mechanism 202 includes opposing axially extending slots 221, as illustrated. The portions of the sheath 212 that have been peeled away extend through these slots as illustrated. The locking mechanism 220 is secured to the depth stop/tubular member via locking screw 222.

The targeting cannula 200 is now ready to receive an interventional device therein. As illustrated in FIG. 25, an interventional device 230, such as a brain stimulation lead, is inserted into the locking mechanism and through the removable sheath 212. A locking screw 224 is tightened to secure the interventional device 230 and prevent axial movement thereof.

The targeting cannula 200 can be MRI-visible. In some particular embodiments, the cannula 200 may optionally comprise a plurality of spaced apart microcoils configured to provide data used to provide 3-D dimensional data in MRI 3-D space, such as a trajectory, or 3-D spatial coordinates of position of the cannula 200. The microcoils can each provide data that can be correlated to a three-dimensional (X, Y, Z) position in 3-D space in the body. The microcoils can be in communication with the MRI scanner, and tracking sequences can be generated and data from one or more of the MRI scanner channels can be used to define positional 3-D positional data and a trajectory thereof.

In some particular embodiments, the progress of the cannula 200 and/or interventional probe 230 or other device may optionally be tracked in substantially real-time as it advances to the target via the coils (similar ones of which may also or alternatively be on or in the probe or other device) and/or antenna. However, real-time tracking may not be desired in some embodiments.

In some embodiments, the cannula 200 can include at least one axially extending fluid-filled hollow lumen (FIG. 8B) or closed channel with fluid that can generate MRI signal that can be detected by an MRI scanner and/or by an internal MRI antenna incorporated on and/or into the cannula 200 that can increase the SNR of the fluid to increase its visibility in an MRI. The fluid may be an aqueous solution (able to resonate at the proton frequency). The cannula 200 can include an axially extending, relatively thin segment, which creates a high contrast MRI image (a segment filled with water or other suitable contrast solution filled section/lumen). The thickness of the segment may be between about 0.25-15 mm (and the segment can have a tubular shape with a diameter or may define another cross-sectional shape such as a square section). The cannula 200 may include MRI imaging coils to increase the signal from the high contrast fluid. See, e.g., co-pending U.S. patent application Ser. No. 12/066,862, which is incorporated here by reference in its entirety.

As illustrated in FIGS. 26A and 26B, the interventional device 230 is positioned at the desired location within the body of a patient. The removable sheath 212 is then completely removed by pulling apart the opposing tabs 214 a, 214 b. A clamp 240 (FIG. 27) is inserted within the burr hole ring 12 that grips the interventional device 230 to prevent inadvertent removal of the interventional device 230 from the body of the patient. The clamp 240 is secured to the burr hole ring 12. The frame 100 can then be removed from the body of the patient, leaving behind only the interventional device 230 that has been inserted into the patient body.

FIGS. 28A-28G are side view, schematic illustrations of the trajectory frame 100 illustrating an exemplary series of operations for the insertion of interventional devices within the body of a patient via the targeting cannula 200. In FIG. 28A, the locking mechanism 220, depth stop 210, and removable sheath 212 are positioned within the targeting cannula 200. In FIG. 28B, an interventional device, e.g., lead 230, is inserted within the sheath 212 and into the brain of the patient. The locking mechanism 220 secures the lead against axial movement (FIG. 28C). The targeting cannula 200 is then retracted (FIGS. 28D-28E). The locking mechanism 220 is unlocked (FIG. 28F) and the frame 100 is removed from the skull of the patient (FIG. 28G).

In some embodiments of the present invention, a video imaging device (e.g., a fiber optic probe with visual access to the burr hole 10 and/or trajectory frame 100 in communication with a camera and display in a clinician workstation) 500 for viewing the burr hole 10 is removably secured to the frame 100 or to the targeting cannula tubular member 204 via a bracket 502. For example, as illustrated in FIG. 13A, a bracket 502 is secured to the targeting cannula tubular member 204. The illustrated bracket 502 is configured to adjustably slide axially along the tubular member 204 for positioning. The illustrated bracket 502 includes a sleeve 504 that is configured to slidably receive an imaging device 500 therein. Threaded locking device 506 is configured to secure the imaging device 500 in position within the sleeve 504 for positioning of the imaging device 500 relative to the body of a patient. A clinician views images captured by the video imaging device 500 via a monitor, as illustrated in FIG. 13B.

In the illustrated embodiment of FIG. 29, a sterile drape 600 is provided for holding the remote control unit 400. The drape 600 is configured to be positioned near the body of a patient and includes a pocket 602 configured to removably receive the remote control unit 400 therein. The drape 600 also includes an aperture 604 through which the cables 150 a-150 b extend from the remote control unit 400 to the frame 100. In the illustrated embodiment, the drape 600 is attached to the magnet housing M of an MRI scanner system.

In some embodiments, the control cables 150 a-150 d are configured to have a limited length. Accordingly, as illustrated in FIG. 30, a safety lanyard 700 may be attached to the remote control unit 400 and to a rigid object to prevent inadvertent detachment of the control cables 150 a-150 d from the frame actuators 140 a-140 d caused by moving the remote control unit 400 too far from the frame 100.

Operations associated with a typical surgical procedure using the trajectory frame 100, according to some embodiments of the present invention, will now be described. These operations relate to deep brain stimulation procedures. Embodiments of the present invention are not limited to use with deep brain stimulation procedures, however.

Initially, a patient is placed within an MR scanner and MR images are obtained of the patient's head that visualize the patient's skull, brain, fiducial markers and ROI (region of interest or target therapeutic site). The MR images can include volumetric high-resolution images of the brain. To identify the target ROI, certain known anatomical landmarks can be used, i.e., reference to the AC, PC and MCP points (brain atlases give the location of different anatomies in the brain with respect to these point) and other anatomical landmarks. The location of the burr hole 10 may optionally be determined manually by placing fiducial markers on the surface of the head or programmatically by projecting the location in an image.

Images in the planned plane of trajectory are obtained to confirm that the trajectory is viable, i.e., that no complications with anatomically sensitive areas should occur. The patient's skull is optically or manually marked in one or more desired locations to drill the burr hole. The burr hole 10 is drilled and a burr hole ring 12 is affixed to the skull overlying the burr hole.

The trajectory frame 100 is then fixed to the skull of the patient and the targeting cannula 200 is properly fitted thereto. A localization scan is obtained to determine/register the location of the targeting cannula 200, in direct orientation of the trajectory frame 100. The settings to which the trajectory frame 100 should be adjusted are electronically determined so that the targeting cannula 200 is in the desired trajectory plane. Frame adjustment calculations are provided to a clinician who can manually or electronically adjust the orientation of the frame 100. The desired trajectory plane is confirmed by imaging in one or more planes orthogonal to the desired trajectory plane.

Once the targeting cannula 200 has the desired trajectory plane, the probe 217 and delivery sheath 212 are advanced through the targeting cannula 200. The advancement of the probe 217 is monitored by imaging to verify that the probe will reach the target accurately. If the probe 217 and delivery sheath 212 are at the desired target, the sheath is left in place and the probe 217 is removed. The sheath 212 will now act as the delivery cannula for the implantable lead 230.

If the probe 217 and delivery sheath 212 are not at the desired/optimal location, a decision is made as to where the probe 217 and delivery sheath 212 need to be. The sheath 212 and the probe 217 are withdrawn from the brain. The trajectory frame 100 is adjusted accordingly via the actuators 140 a-140 d and the probe 217 and delivery sheath 212 are re-advanced into the brain. Once the probe 217 and delivery sheath 212 are at the desired location, the probe 217 is removed and the delivery sheath is left in place. The lead 230 is then advanced to the target location using the sheath 212 as a guide. The location of the lead is confirmed by reviewing an image, acoustic recording and/or stimulation. The sheath 212 is then removed, leaving the lead in place.

It is contemplated that embodiments of the invention can provide an integrated system 50 that may allow the physician to place the interventional device/leads accurately and in short duration of time. In some embodiments, once the burr hole is drilled, and the trajectory frame is fixed to the skull; the trajectory frame is oriented such that the interventional device advanced using the trajectory frame follows the desired trajectory and reaches the target as planned in preoperative setup imaging plans. As described herein, the system 50 can employ hardware and software components to facilitate an automated or semiautomated operation to carry out this objective.

With reference to FIGS. 33-38, a trajectory guide frame 1100 according to further embodiments of the present invention is shown therein. The frame 1100 can be generally constructed and used in the same or similar manner as discussed above with regard to the trajectory guide frame 100, except as discussed herein. The frame 1100 includes a base 1110, a yoke 1120, a platform 1130, a targeting cannula 1200 (FIG. 38), and a tubular trajectory guide member 1204 corresponding to the components 110, 120, 130, 200 and 204, respectively, of the frame 100. The targeting cannula 1200 has a guide lumen tube 1258 (FIG. 38) to receive an interventional device. The targeting cannula 1200 can slide up and down in the passage 1204C (FIG. 38) of the targeting cannula guide member 1204 as discussed above with the targeting cannula 200 and the guide member 204. The frame 1100 further includes a scope bracket 1502. The bracket 1502 can be used to selectively and adjustably secure an imaging device, a light transmission scope or other suitable device.

The light transmission scope can include an optical fiber scope 1552 connected to a video camera 1551 (schematically illustrated in FIG. 33), for example, which is in turn connected to a display such as the display 500 (FIGS. 1 and 33). The fiber scope 1552 may include an inner tube 1554 containing a bundle of optical fibers, and an outer tubular jacket 1556 surrounding a portion of the inner tube 1554. A lens 1558 can be provided at the terminal end of the inner tube 1554. The optical fibers can transmit light to the camera 1551. Optical fibers may also be provided in the inner tube 1554 to transmit light from a light source 1553 to the terminal end of the fiber scope 1552 to illuminate the local region (e.g., burr hole) observed via the lens 1558.

Turning to the bracket 1502 in more detail and with reference to FIG. 36, the bracket 1502 includes a frame mount collar or portion 1504, a camera probe mount portion 1506, and a connector leg 1508 joining the portions 1504, 1506. A lock screw 1510A is provided in the frame mount portion 1504 and a lock screw 1510B is provided in the camera probe mount portion 1506. The frame mount portion 1504 includes opposed clamp arms 1512. Opposed projections 1514A and 1514B extend inwardly from the clamp arms 1512. A bore 1516 (FIG. 38) is defined in the bracket 1502 and has an upper section 1516A and a lower section 1516B, the lower section 1516B having a reduced diameter as compared to that of the upper section 1516A.

Opposed arcuate, circumferential mount grooves 1204A and 1204B (FIGS. 36 and 37) are defined in the outer surface of the targeting cannula guide member 1204. The clamp arms 1512 are engaged about the guide member 1204 with the projections 1514A and 1514B seated in or mating with the grooves 1204A and 1204B, respectively. In this manner, the bracket 1552 is secured to the guide member 1204 beneath the yoke 1120. The bracket 1502 may be further secured to the guide member 1204 by tightening the lock screw 1510A.

In use, the fiber scope 1552 is inserted through the bore 1516 such that the outer jacket 1556 is received in the bore section 1516A, the inner tube 1554 is received in the bore section 1516B, and the lens 1558 is directed at the patient access aperture 1112 and the burr hole, when present. The fiber scope 1552 may be secured in the bracket 1502 by tightening the lock screw 1510B.

The bracket 1502 can be rotated in each of opposed rotation directions R1 and R2 (FIGS. 35 and 37) about the trajectory axis TCA (defined by the guide bore or lumen 1250 (FIG. 37) of the targeting cannula 1200 (FIG. 38)) by rotating the clamp arms 1512 circumferentially about the guide member 1204. The relative dimensions of the projections 1514A, 1514B and the grooves 1204A, 1204B may permit the bracket 1502 to rotate within a prescribed range. The prescribed range of rotation can be selected to prevent or reduce the risk of interference between the bracket 1502 and the yoke 1120. According to some embodiments, the range of rotation is less than 180 degrees on each side of the yoke 1120. According to some embodiments, the range of rotation is in the range of from about 10 to 80 degrees on each side of the yoke 1120. The bracket 1502 can be locked in a selected rotational position by tightening the lock screw 1510A.

While the bracket 1502 can be rotated about the guide member 1204 and the trajectory axis TCA, the axial position of the bracket 1502 along the trajectory axis TCA is fixed. The engagement between the projections 1514A, 1514B and the grooves 1204A, 1204B prevents the bracket 1502 from moving up or down (i.e., axially along) the guide member 1204. In this manner, a desired distance between the lens 1558 and the patient access aperture 1112 can be reliably maintained.

The position of the bracket 1502 on the guide member 1204 can also be reversed so that the bracket 1502 extends from the opposite side of the yoke 1120. More particularly, the clamp arms 1512 can be mounted on the guide member 1204 such that the projections 1514A and 1514B slidably seat in the grooves 1204B and 1204A, respectively. FIG. 34 illustrates various positions of the bracket 1502 on either side of the frame 1100 and across an exemplary range of rotational positions on each side.

In some applications, the bracket 1502 may be mounted on the guide member 1204 as described above without tightening the screw 1510A. In this case, the bracket 1502 may be free to rotate about the guide member 1204 if the bracket 1502 is struck by the yoke 1120, thereby preventing binding or interference with the operation of the yoke 1120.

Other types of light transmission scopes 1552 and associated devices may be employed in accordance with embodiments of the present invention. In some embodiments, the light transmission scope 1552 is a laser transmission scope operatively connected to a laser generator to direct a laser beam at the patient through the patient access opening 1112. In some embodiments, the light transmission scope 1552 is operatively connected to a light source without provision of a camera device.

According to some embodiments, the bracket 1502 is configured such that, when a fiber scope 1552 of prescribed dimensions is inserted in the bore 1516, the outer jacket 1556 bottoms out in the bore 1516A and the lens 1558 projects a prescribed distance below the bracket 1502. In this manner, the lens 1558 is disposed at a prescribed distance from and angle with respect to the access opening 1112 and the burr hole.

Referring to FIG. 36, according to some embodiments, the bracket 1502 can be readily snapped on and off of the guide member 1204. The bracket 1502 may be formed of a resilient semi-rigid material permitting sufficient deflection of the clamp arms 1512 to release the projections 1514A, 1514B from the grooves 1204A, 1204B when desired.

With reference to FIGS. 33 and 38-40, the targeting cannula 1200 of the frame 1100 corresponds to the targeting cannula 200 of the frame 100 except as follows. The frame 1100 and targeting cannula 1200 can be used in the same manner as the frame 100 and the targeting cannula 200 and are further modified or configured to facilitate insertion of an interventional device 1217 (e.g., a probe, sheath, stylet, or the like; shown in dashed lines in FIG. 40) into and through the targeting cannula 1200.

The targeting cannula 1200 can be slid up and down in the passage 1204C of the guide member 1204 as discussed above with regard to the targeting cannula 200 and the guide member 204 to place (and, in some embodiments, secure) the targeting cannula 1200 in a raised or retracted position as shown in FIG. 38 and in a lowered or extended position as shown in FIG. 40.

Referring to FIG. 38, the targeting cannula 1200 has a guide lumen tube 1258. The targeting cannula 1200 has an inlet 1252 and an outlet 1254 on the trajectory axis TCA and communicating with the guide bore 1250 of the guide lumen tube 1258 on the upper and lower ends thereof. An annular tapered wall 1256 extends inwardly from the inlet 1252 to an inner opening 1257.

A guide member support cap 1261 is mounted on the upper end of the tubular guide member 1204. The cap 1261 has a through bore 1260 (FIG. 40) and an inlet 1262 (FIG. 40) communicating with the bore 1260. An annular wall 1264 (FIGS. 39 and 40) tapers from the inlet 1262 to a narrowed (as compared to the inlet 1262) passage 1266.

As shown in FIG. 39, according to some embodiments, the inlet 1252 of the targeting cannula 1200 has a diameter D1 (FIG. 39) that is at least 20% greater than the diameter D2 of the inner opening 1257 and the guide bore 1250. According to some embodiments, the taper angle of the tapered wall 1256 with respect to the trajectory axis TCA is in the range of from about 20 to 70 degrees. According to some embodiments, the depth from the inlet 1252 to the inner opening 1257 is in the range of from about 0.01 to 0.1 inch.

According to some embodiments, the inlet 1262 of the support cap 1261 has a diameter D4 that is at least 5% greater than the diameter D5 (FIG. 39) of the passage 1266 (FIG. 40). According to some embodiments, the taper angle of the tapered wall 1264 (FIG. 40) with respect to the trajectory axis TCA is in the range of from about 20 to 70 degrees.

The enlarged, tapered inlet 1252 aids the operator (e.g., physician) in inserting the elongate interventional device 1217 into the targeting cannula 1200. The tapered wall 1258 can also aid the operator in fully feeding the interventional device 1217 through the guide bore 1250. This assistance may be particularly advantageous when the interventional device 1217 is to be inserted into the targeting cannula 1200 while the targeting cannula 1200 is in its extended position (FIG. 40) and/or the patient is in the bore of a magnet limiting a clinician's access to the cannula. Insertion of the interventional device 1217 may be further facilitated by the enlarged, tapered inlet 1262 of the support cap 1261.

With reference to FIG. 41, the frame 1100 is shown therein with an alternative targeting cannula 1200′ mounted in the guide member 1204 in place of the targeting cannula 1200 according to further embodiments of the present invention.

The targeting cannula 1200′ can be configured in the same manner as the targeting cannula 1200 but further includes a tubular extension 1259′ having a reduced outer diameter D6 as compared to the inner diameter of the guide member passage 1204C. The reduced outer diameter of the extension 1259′ permits the extension 1259′ to be received into or through the passage 1266 of the support cap 1261 when the targeting cannula 1200′ is in the retracted position as shown in FIG. 41.

According to some embodiments, when the targeting cannula 1200′ is in the retracted position, the tapered wall 1256′ begins below the tapered wall 1264 of the cap 1261 and extends up to a position adjacent or overlapping with the cap 1261 to provide a continuous tapered wall from the opening 1262 to the inner opening 1257′. According to some embodiments, the top of the extension 1259′ is substantially flush with the top of the narrowed passage 1266 of the cap 1261 when the targeting cannula 1200′ is in the retracted position.

The extension 1259′ provides additional length to the targeting cannula 1200′ so that, when the targeting cannula 1200′ is in its extended position, the distance between the inlet 1252′ and the inlet 1262 is reduced, thereby making it easier for the operator to insert the interventional device 1217 through the guide bore 1250′. By configuring the extension 1259′ to be flush with but not extend above the upper end of the passage 1266 of the cap 1261, interference between the extension 1259′ and other components mounted on the cap 1261 (e.g., the depth stop 220) can be prevented.

With reference to FIGS. 33 and 42-44, the frame 1100 can include a mounting system 1101 configured to allow assembly of the yoke 1120 onto the base 1110 by an operator or the like when desired. According to some embodiments, the mounting system 1101 also permits the yoke 1120 to be dismounted from the base 1110 when desired. As discussed in more detail below, the mounting system 1101 can be configured to prevent or reduce the risk of installing the yoke 1120 on the base 1110 with an orientation other than a prescribed orientation.

A first part of the mounting system 1101 may be integrated into the base 1110. The base 1110 includes a hub 1111 defining the patient access opening 1112 and which can be secured to the patient by screws inserted through the screw holes 1114. A pair of struts 1115 extend from the hub 1111 to support first and second arcuate rails or arms 1116A and 1116B. A first mount tab or extension 1160 depends from the first arm 1116A and a second mount tab or extension 1162 depends from the second arm 1116B. A generally vertical first mount slot 1161 is provided in the first extension 1160 (accessible via the outer wall). The first mount slot 1161 has a slot inlet 1161A on its upper end and a pivot hole 1161B on its lower end. A generally vertical second mount slot 1163 is provided in the second extension 1162. The second mount slot 1163 has a slot inlet 1163A on its upper end and a pivot hole 1163B on its lower end.

The yoke 1120 has first and second depending mount wings, tabs or arms 1164 and 1165. As shown in FIG. 44, a mount hole 1164A is formed in the mount arm 1164 and has internal threads 1164B (FIG. 44). A mount hole 1165A is formed in the mount arm 1165 and has internal threads 1165B (FIG. 44).

As shown in FIGS. 42 and 44, the mounting system 1101 further includes first and second pivot screws 1166 and 1167 each including a respective knob 1166A, 1167A, an externally threaded shank 1166B, 1167B, and a smooth pivot pin or post 1166C, 1167C. The first pivot screw 1166 is screwed into the first mount hole 1164A such that the pivot post 1166C projects inwardly beyond the hole 1164A. The second pivot screw 1167 is screwed into the second mount hole 1165A such that the pivot post 1167C projects inwardly beyond the hole 1165A.

Referring to FIG. 42, to assemble the frame 1100, the yoke 1120 can be mounted on the base 1110 as follows. According to some embodiments, the yoke 1120 is mounted on the base 1110 before the base 1110 is mounted on the patient and, according to some embodiments, after the frame 1100 components are shipped from the manufacturer to the end user. According to some embodiments, the platform 1130, the targeting cannula 1200, and the guide member 1204 are preassembled by the manufacturer onto the yoke 1120.

With the pivot screws 1166, 1167 installed in the holes 1164A, 1165A and the opposed posts 1166C, 1167C projecting inwardly toward one another, the posts 1166C and 1167C are positioned above the slots 1161, 1163 and aligned with the slot inlets 1161A and 1163A, respectively. The yoke 1120 is lowered onto the arcuate arms 1116 of the base 1110 such that the posts 1166C and 1167C slide into the slots 1161 and 1163, respectively, through the slot inlets 1161A and 1163A. The assembler continues to lower the yoke 1120 so that the posts 1166C, 1167C slide down the slots 1161, 1163 until the posts 1166C and 1167C align with the pivot holes 1161B and 1163B, respectively, whereupon the posts 1166C and 1167C seat within the pivot holes 1161B and 1163B. The yoke 1120 is thereby mounted on the base 1110 to pivot about the roll axis RA (i.e., about the pivot posts 1166C, 1167C) as discussed above with regard to the frame 100, the yoke 120 and the base 110.

According to some embodiments, the spacing between the slots 1161, 1163 is greater than the spacing between the posts 1166C, 1167C and the mount extensions 1160, 1162 are resilient so that the extensions 1160, 1162 are deflected outwardly until the posts align with the pivot holes 1161B, 1163B, whereupon the spring bias of the mount extensions 1160, 1162 forces the posts 1166C, 1167C to seat or snap fit into the respective pivot holes 1161B, 1163B. In this manner, unintended disengagement between the posts 1166C, 1167C and the pivot holes 1161B, 1163B can be prevented or inhibited by the persistent spring bias resisting removal of the posts 1164C, 1165C from the pivot holes 1161B, 1163B. The amount of spring loading between the posts 1166C, 1167C and the mount extensions 1160, 1162 can be adjusted by screwing the pivot screws 1166, 1167 into or out of the mount holes 1164A, 1165A.

According to some embodiments, the bottom walls of the opposed slots 1161, 1163 taper outwardly with respect to one another in the direction from the slot inlets 1161A, 1163A to the pivot holes 1161B, 1163B. With this configuration, it may be easier for the assembler to initiate insertion of the posts 1166C, 1167C into the slots 1161, 1163 with greater resistance being presented as the posts 1166C, 1167C travel down the slots 1161, 1163 and outwardly deflect the mount arms 1164, 1165. According to some embodiments, the slots 1161, 1163 taper outwardly at an angle of between about 1 and 15 degrees with respect to one another.

If desired, the yoke 1120 can be dismounted from the base 1110 by pulling the mount arms 1164, 1165 apart to release the posts 1166C, 1167C from the pivot holes 1161B, 1163B and sliding the posts 1166C, 1167C back up and out of the slots 1161, 1163. The pivot screws 1166, 1167 can be screwed outwardly so that it is not necessary to spread the arms 1164, 1165 to release the posts 1166C, 1167C. If desired, the screws 1166, 1167 can be fully removed from the yoke 1120. The knobs 1166A, 1167A can be grasped and pulled by the operator to pull the arms 1164, 1165 apart.

According to some embodiments, the first and second posts 1166C, 1167C have different diameters D7 (FIG. 43) and D8 (FIG. 42) from one another, the first and second slots 1161, 1163 have different widths W1 (FIG. 42) and W2 (FIG. 43) from one another, and the first and second pivot holes 1161B and 1163B have different diameters W1′ and W2′ (FIG. 44) from one another. More particularly, the diameter D7 is greater than the width W2 and the diameter W2′ and somewhat less than the width W1 and the diameter W1′. The diameter D8 is somewhat less than the width W2 and the diameter W2′. As a result, the first post 1166C can only be inserted into the first slot 1161, thereby preventing the assembler from mounting the yoke 1120 on the base 1110 with the wrong relative orientation between the base 1110 and the yoke 1120.

With reference to FIGS. 33, 38, 45 and 46, the frame 1100 may further include a stabilizer system 1171 (FIG. 45) to control relative movement between the moving plate 1134 and a support table 1132 thereof (corresponding to the moving plate 134 and the support table 132, respectively, of the frame 100). The stabilizer system 1171 can thereby control relative movement between the targeting cannula 1200 and the platform 1130.

The support table 1132 has sideward opening slots 1132A through which ends of the moving plate 1134 slide when the moving plate 1134 is translated in the X-direction or the Y-direction with respect to the support table 1132. The stabilizer system 1171 includes a pair of opposed stabilizer mechanisms 1170 mounted in respective ones of the slots 1132A. The stabilizer mechanisms 1170 can be configured and used in the same manner and only one of the stabilizer mechanisms 1170 will be described in detail hereinafter, it being appreciated that this description likewise applies to the other stabilizer mechanism 1170.

Referring to FIGS. 45 and 46, the stabilizer mechanism 1170 includes a pressure member or bearing or rub bar 1172 and set screws 1174. The rub bar 1172 is mounted in the slot 1132A between the top of the moving plate 1134 and an overlying crossbar 1132B of the support table 1132. The set screws 1174 are threadedly mounted in the threaded bores 1176 in the crossbar 1132B and extend into a groove 1172B in the rub bar 1172 to retain the rub bar 1172 in the slot 1132A. The rub bar 1172 may include indicia 1172C corresponding to the indicia 138 of the frame 100 and cooperating with a scale 1136 on the moving plate 1134.

The screws 1174 and bores 1176 can serve as an adjustment mechanism by rotating the screws 1174 in or out with respect to the crossbar 1132C to selectively adjust the height H of the slot 1132A. In this manner, the slack or gap between the moving plate 1134 and the support table 1132 in the slot 1132A can be reduced or effectively eliminated.

According to some embodiments, the screws 1174 and the threaded bores 1176 serve as a loading mechanism to apply a load to the rub bar 1172. More particularly, the operator or assembler can rotate the screws to force the rub bar 1172 to compressively load the moving plate 1134 via an engagement surface 1172A of the rub bar 1172. The rub bar 1172 may present a frictional resistance to sliding motion of the moving plate 1134.

According to some embodiments, the operator or assembler sets the compressive load on the moving plate 1134 using the stabilizer mechanisms 1170 at a level that permits the moving plate 1134 to slide in the slots 1132A without binding but which does not permit significant movement between the moving plate 1134 and the support table 1132 other than in the X and Y directions. According to further embodiments, the screws 1174 are adjusted so that the rub bar 1172 does not compressively load the moving plate 1172.

The stabilizer system 1171 can be used to prevent or reduce tilting of the moving plate 1134, and thus the targeting cannula 1200, relative to the support table 1132 and the base 1110. The stabilizer system 1171 can correct for oversized tolerances between the moving plate 1134 and the support table 1132 (e.g., from manufacturing and/or usage of the frame 1100).

With reference to FIGS. 38, 47 and 48, the frame 1100 can include a lock system 1179 to temporarily prevent or resist movement of the upper (i.e., Y-direction movement) moving plate 1134 and/or the lower (i.e., X-direction movement) moving plate 1135 (FIG. 46) with respect to the support table 1132. Such movement control may be desirable to prevent damage to the frame 1110 during shipping and/or to prevent unintended X-Y displacement of the targeting cannula 1200 when setting the targeting trajectory, for example.

With reference to FIG. 38, the lock system 1179 includes a lock clip 1178, a through hole 1134L (in the upper moving plate 1134), a through hole 1135L (in the lower moving plate 1135), and a hole 1132L (in the support table). As shown in FIG. 48, the lock clip 1178 may be generally U-shaped and integral with a lock leg 1178A, a clip leg 1178B, a bend 1178C, and a latch feature 1178D. The lock clip 1178 may be formed of any suitable MRI-compatible material, such as a substantially rigid polymeric material.

In use, the lock leg 1178A of the lock clip 1178 is inserted through the holes 1134L, 1135L, 1132L and the latch feature 1178D is secured underneath a protruding end portion of the upper moving plate 1134 (see FIGS. 38 and 47). According to some embodiments, the lock clip 1178 is installed at the assembly factory. The lock clip 1178 may be retained in the locking position until after the frame 1110 is mounted on the patient's head, for example. The lock clip 1178 can be removed from the platform 1130 by pulling the latch feature 1178D free of the end of the moving plate 1134 and withdrawing the lock leg 1178A from the holes 1134L, 1135L, 1132L.

With reference to FIG. 49A, according to some embodiments, fiducial markers are relatively configured on the frame 1100, and in some embodiments on the base 1110, in a manner that facilitates or enables positive determination of an orientation of the frame 1100 from an MR image. According to some embodiments, the spacing between adjacent fiducial markers on the frame 1100 (e.g., on the base 1110) is non-uniform. According to some embodiments, the fiducial markers are mounted on the frame 1100 in a rotationally asymmetric layout. For example, according to some embodiments, the fiducial markers 1182, 1184, 1186 are mounted on the base 1110 in a rotationally asymmetric layout or configuration. By reference to this prescribed asymmetry, an affirmative orientation of the base 1110 (and, thus, the frame 1100 and the trajectory guide axis TCA) in free space can be determined from MRI image data of an MR image of the frame 1100.

According to some embodiments, the rotationally asymmetric layout includes locating the fiducial markers such that a first fiducial marker (e.g., the fiducial marker 1184) is closer to an adjacent second fiducial marker (e.g., the fiducial marker 1186) than it is to a third adjacent fiducial marker (e.g., the fiducial marker 1182). According to some embodiments, the rotationally asymmetric layout includes locating the fiducial markers 1182, 1184, 1186 such that two of the fiducial markers 1182, 1184, 1186 are closer to one another than either is to the third. According to some embodiments and as illustrated, the fiducial markers 1182, 1184, 1186 are positioned on the base 1110 such that their center points (i.e., the center points of their center openings 1187C) are each located on a circle C. The fiducial markers 1184 and 1186 are circumferentially spaced apart from one another on the circle C a shorter distance than either fiducial marker 1184, 1186 is circumferentially spaced apart from the fiducial marker 1182 (i.e., the arc lengths of the circle segments between the fiducial markers 1184, 1186 and the fiducial marker 1182 are greater than the arc length of the circle segment between the fiducial markers 1184, 1186).

In some embodiments, the center point CP of the circle C is substantially coincident with the center point of the patient access opening 1112. According to some embodiments, the center point CP lies on the guide axis TCA (FIG. 38) when the targeting cannula 1200 is positioned in a top dead center position with respect to the base 1110 and the frame 1100 is in a home position as shown in FIGS. 33, 34, 38 and 47. According to some embodiments, when the frame 1100 is in the home position, the trajectory guide axis TCA is substantially orthogonal with the plane of the patient access opening 1112 or the burr hole. According to some embodiments, when the lock clip 1178 is in the locking position (FIGS. 38 and 47) the trajectory guide axis TCA intersects the center point CP irrespective of the pitch or roll setting of the frame 1100 (e.g., the center point CP may be coincident with the remote center of motion (RCM)).

According to some embodiments, the fiducial markers 1182, 1184, 1186 and the circle C all lie on a common fiducial marker plane F-F (FIGS. 38 and 44). According to some embodiments, the fiducial marker plane F-F is spaced apart above (and in some embodiments, parallel to) the plane of the patient access opening 1112 and the burr hole (when mounted on the patient).

According to some embodiments, the frame 1100 is secured to the patient's head and the patient is placed within the MRI scanner 75. The MRI scanner scans the patient and the frame 1100 and generates corresponding MR image data. From the MR image data, MR images are obtained of the patient's head that visualize the patient's skull and brain. Certain known anatomical landmarks can be included in the MR images. The MR images also visualize the MRI-visible fiducial markers 1182, 1184, 1186, which serve as MRI-visible landmarks associated with the frame 1100. The MR images can include volumetric high-resolution images of the brain.

With reference to FIG. 49B, the location and orientation of the frame 1100 on the head is identified in the MR images. Certain known anatomical landmarks can be used. For example, reference may be made to physiological landmarks such as the AC, PC and MCP points (brain atlases give the location of different anatomies in the brain with respect to these points) and other anatomical landmarks of the patient's head.

The location and orientation of the frame 1100 may be determined by visually displaying the fiducial markers 1182, 1184, 1186 or representations thereof in an image 40 on the display 500 where they can be readily identified by the operator (for example, as shown in FIG. 49B). The image 40 may further include the MR image of the patient 11. The operator can determine the orientation of the base 1110 on the patient's head and in free space by determining the relative positions of the fiducial markers 1182, 1184, 1186.

Alternatively or additionally, an electronic controller 302 may programmatically identify or recognize and analyze and/or report and/or visualize the fiducial markers 1182, 1184, 1186 in the image data.

According to some embodiments, the controller 302 processes the acquired image data to programmatically recognize, orient and place the base 1110 in the logical space (i.e., MR volume) frame of reference. According to some embodiments, the controller 302 uses an algorithm to programmatically determine the position of the base 1110 in the logical space. According to some embodiments, the controller 302 uses a pre-stored reference image or images to programmatically determine the position of the base 1110 in the logical space.

Once the controller 302 has assessed the position (e.g., including orientation) of the base 1110 in the logical space, the controller 302 can use this data to assess or track the frame 1100 or enable or assist identification of the frame orientation by the operator. For example, the controller 302 may enhance (e.g., add increased image contrast) or insert highlighted representations of the fiducial markers 1182, 1184, 1186 into the image 40 as provided on the display 500 in order to make the fiducial markers 1182, 1184, 1186 visually stand out in the image 40. The controller 302 can provide various additional functionality once it has recognized the fiducial markers 1182, 1184, 1186 in the MR image. Further methods and operations of the controller are disclosed in U.S. patent application Ser. No. 12/236,854, filed Sep. 24, 2008 [Attorney Docket No. 9450-341P4], the disclosure of which is incorporated herein by reference.

According to some embodiments, the controller 302 generates, fits and overlays or superimposes a graphical grid overlay 45 onto the MR image 40 as shown in FIG. 49B, for example, to delineate the location and distribution of the fiducial markers 1182, 1184, 1186, the base 1110 and/or the access opening 1111 on the head 11. The positions and orientations of fiducial markers 1182, 1184, 1186 or the base 1110 may be correlated to the image of the head 11 by the graphical grid overlay 45. According to some embodiments, the controller 302 processes the MR image without displaying the fiducial markers 1182, 1184, 1186 and/or the grid overlay 45 to the operator.

With reference to FIGS. 44, 49A and 50, the frame 1100 may be provided with features to reliably and accurately locate the fiducial markers 1182, 1184, 1186 on and with respect to the base 1110. The fiducial markers 1182, 1184, 1186 are each toroidal in shape and have a central opening 1187C. As shown in FIGS. 42, 43 and 49A, the base 1110 can include cavities 1110A′, 1110B′, and 1110C′, defined in part by platforms 1110A, 1110B, 1110C, configured to receive the fiducial markers 1182, 1184, and 1186, respectively. The base 1110 further includes a central locator projection 1111 in each cavity 1110A, 1110B, 1110C extending up from the platform 1110A′, 1110B′, and 1110C′ thereof. When the fiducial markers 1182, 1184, 1186 are mounted in the cavities 1110A, 1110B, 1110C, each location projection 1111 is received in the respective central opening 1187C to positively locate the fiducial marker 1182, 1184, 1186 in the cavity 1110A, 1110B, 1110C. According to some embodiments, each locator projection 1111 is located on the circle C (FIG. 49A).

According to some embodiments, the outer diameter of each locator projection 1111 is substantially the same as the inner diameter of the receiving central opening 1187C.

With reference to FIG. 51, each fiducial marker 1182, 1184, 1186 may include a torus body 1187A (surrounding the central opening 1187C) and a fill nipple or tab 1187B extending radially from the body 1187A. The fill tab 1187B may be a manufacturing artifact from a tube used to fill the body 1187A with an MRI-visible material such as an MRI-visible liquid, for example. Suitable fiducial markers may include donut-shaped markers available from Beekley Corporation.

The seat cavity 1110A substantially fully (i.e., 360 degrees) circumferentially surrounds the fiducial marker 1182 when the fiducial marker 1182 is installed on the base 1110. However, in order to accommodate the tab 1187B of the fiducial marker 1182, a relief or cutout 1110D is formed in the base 1110 at or contiguous with the cavity 1110A. The tab 1187B of the fiducial marker 1182 extends through the cutout 1110D.

The order steps may be different from that described herein and not all steps may be used or some of the steps may be used with other steps. In some embodiments, the frame 1100 can be mounted and assembled in a different order than that set forth above. According to some embodiments, the frame 1100 is mounted on the patient and assembled as follows. The burr hole is formed. The base 1100 is then mounted on the head about the burr hole. A burr hole ring is then mounted on the burr hole through the access opening 1112. According to some embodiments, the access opening 1112 is sized and shaped to prevent contact between the burr hole ring and the base 1110 when both are mounted on the patient's head. The yoke 1120 is then mounted on the base 1110 (e.g., in the manner described above). According to some embodiments, the yoke 1120 is removed from the base 1110 after the interventional procedure is executed using the frame 1100 in order to facilitate access to the screws securing the base 1110 to the head. The screws can then be removed to dismount the base 1110 from the head.

According to some embodiments, the lock clip 1178 is retained in the locking position (FIGS. 38 and 47) at least until the yoke 1120 is mounted on the base 1110. According to some embodiments, the lock clip 1178 is retained in the locking position at least until the pitch and roll adjustments have been made to place the targeting cannula 1200 in the desired orientation. The lock clip 1178 may thereafter be removed in order to make an X-Y adjustment or adjustments to the targeting cannula 1200.

As discussed above with reference to FIG. 10A, the remote control unit 400 may include locking mechanisms 401 a, 404 b, 404 c to secure the settings of the frame 1100. Additionally or alternatively, the frame 1100 may be constructed and configured to effectively self-lock the positions of the frame 1100 (i.e., the settings of the yoke 1120, the support table 1132, the X-direction moving plate 1134 and the Y-direction moving plate 1135) up to at least a prescribed load, in which case the locking mechanisms 404 a, 404 b, 404 c may be omitted or remain unused. More particularly, according to some embodiments, the tolerances between the relatively movable components of the frame 1100 and/or the resistance of the onboard adjustment mechanisms (e.g., the gear drives) are selected such that at least a relatively high prescribed threshold force or torque must be applied to each respective actuator 1140 a, 1140 b, 1140 c, 1140 d (FIG. 33) in order to change the corresponding roll, pitch, X or Y adjustment (i.e., to change the relative position of the corresponding component). With respect to the X and Y adjustments, this may be accomplished by adjusting the stabilizer systems 1171 so that the rub bars 1172 sufficiently bear upon the moving plate 1134. The drive shafts or control cables 150 a-d can be permitted to float freely.

In some embodiments, the frames 100, 1100 are sized and shaped so that they may be simultaneously mounted side-by-side on a patient's head to conduct a bilateral surgical procedure as described herein without contacting or interfering with one another as illustrated in FIG. 52.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein. 

1. An MRI-guided interventional system for use with a body of patient and an interventional device, the system including: a trajectory guide frame for guiding the interventional device with respect to a body of a patient in an MRI-guided procedure, the trajectory guide frame including: a base having a patient access aperture therein, wherein the base is configured to be secured to the body of the patient; a platform mounted on the base and including a support table and a moving plate that is translatable relative to the support table and the base along a translational axis; a targeting cannula mounted on the moving plate for movement therewith relative to the support table and the base, the targeting cannula including an elongate guide bore therethrough, the guide bore defining a trajectory axis and being configured to guide placement of the interventional device in vivo; and a stabilizer mechanism operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base; wherein the trajectory guide frame is operable to translate the moving plate and thereby the targeting cannula along the translational axis relative to the base to position the trajectory axis to a desired intrabody trajectory to guide placement of the interventional device in vivo; and wherein the translational axis is transverse to the trajectory axis.
 2. The system of claim 1 including an elongate interventional device configured to be serially inserted along the trajectory axis through the guide bore and into the body of the patient in vivo.
 3. The system of claim 1 wherein: the translational axis is an X-translational axis; the moving plate is translatable relative to the support table and the base along a Y-translational axis transverse to the X-translational axis; and the Y-translational axis is transverse to the trajectory axis.
 4. The system of claim 1 further including a yoke movably mounted on the base and rotatable relative to the base about a pivot axis, wherein the platform is mounted on the yoke for rotation therewith and the platform is configured to permit translational movement of the moving plate with respect to the yoke.
 5. The system of claim 1 wherein: the stabilizer mechanism includes an adjustment device and a rub bar; and the rub bar and the support table cooperatively define a slot through which the moving plate slides in contact with the rub bar.
 6. The system of claim 5 wherein the adjustment device includes a loading device operable to apply a load to the rub bar to compressively load the moving plate in the slot between the support table and the rub bar.
 7. The system of claim 5 wherein the loading device includes at least one screw.
 8. A trajectory guide frame for guiding an interventional device with respect to a body of a patient in an MRI-guided procedure, the trajectory guide frame comprising: a base having a patient access aperture therein, wherein the base is configured to be secured to the body of the patient; a platform mounted on the base and including a support table and a moving plate that is movable relative to the support table and the base; a targeting cannula mounted on the moving plate for movement therewith relative to the support table and the base, the targeting cannula including a guide bore therethrough that is configured to guide placement of the interventional device in vivo; and a stabilizer mechanism operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base; wherein: the stabilizer mechanism includes an adjustment device and a rub bar; and the rub bar and the support table cooperatively define a slot through which the moving plate slides in contact with the rub bar.
 9. The trajectory guide frame of claim 8 wherein the adjustment device is operable to apply a load to the rub bar to compressively load the moving plate in the slot between the support table and the rub bar.
 10. The trajectory guide frame of claim 8 wherein the loading device includes at least one screw.
 11. A method of adjusting a trajectory of an in vivo interventional device, comprising: affixing a trajectory guide frame to a body of a patient in an MRI-guided procedure, the trajectory guide frame including: a base having a patient access aperture therein, wherein the base is configured to be secured to the body of the patient; a platform mounted on the base and including a support table and a moving plate that is translatable relative to the support table and the base along a translational axis; a targeting cannula mounted on the moving plate for movement therewith relative to the support table and the base, the targeting cannula including an elongate guide bore therethrough, the guide bore defining a trajectory axis and being configured to guide placement of the interventional device in vivo; and a stabilizer mechanism operable to selectively control movement between the support table and the moving plate to stabilize a position of the targeting cannula with respect to the base; wherein the trajectory guide frame is operable to translate the moving plate and thereby the targeting cannula along the translational axis relative to the base; and wherein the translational axis is transverse to the trajectory axis; and while the patient remains in position in a magnetic field associated with an MRI scanner, adjusting the trajectory guide frame to translate the moving plate and thereby the targeting cannula along the translational axis relative to the base to position the trajectory axis to a desired intrabody trajectory to guide placement of the interventional device in vivo.
 12. The method of claim 11 wherein: the stabilizer mechanism includes an adjustment device and a rub bar; the rub bar and the support table cooperatively define a slot through which the moving plate slides in contact with the rub bar; the adjustment device includes a loading device operable to apply a load to the rub bar to compressively load the moving plate in the slot between the support table and the rub bar; and the method includes selectively operating the loading device to change the compressive load on the moving plate.
 13. An MRI-guided interventional system, comprising: a trajectory guide frame with a cooperating targeting cannula, wherein the trajectory guide frame is configured to translate and rotate such that the targeting cannula can be positioned to a desired intrabody trajectory, and wherein the targeting cannula includes a guide bore therethrough that is configured to guide placement of an interventional device in vivo, wherein the trajectory guide frame comprises: a base having a patient access aperture formed therein, wherein the base is configured to be secured to the body of a patient; a yoke movably mounted to the base and rotatable about a roll axis; a platform movably mounted to the yoke and rotatable about a pitch axis, wherein the platform comprises an X-Y support table and a moving plate, wherein the moving plate is movably mounted to the support table to move in an X-direction and Y-direction relative to the base; and a stabilizer mechanism operable to selectively control movement between the X-Y support table and the moving plate to stabilize a position of the targeting cannula with respect to the base.
 14. The system of claim 13 including at least one user-activatable actuator operably connected to the trajectory guide frame and configured to translate and rotate the trajectory guide frame relative to the body of the patient so as to position the targeting cannula to a desired intrabody trajectory. 